diff --git a/CHANGELOG.md b/CHANGELOG.md
index bfa6a99..72fc505 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## [1.1.0] - 2024-08-12
+- add class `MonopayRuby::Invoices::AdvancedInvoice` where in method `MonopayRuby::Invoices::AdvancedInvoice::create` you can add any necessary params for your app
+- change private method `request_body` to public
+- add more details about `MonopayRuby::Invoices::AdvancedInvoice` into `README.md`
 ## [1.0.0] - 2023-06-27
 
 ### Changed
diff --git a/Gemfile.lock b/Gemfile.lock
index 863fd18..3ef5035 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    monopay-ruby (1.0.0)
+    monopay-ruby (1.1.0)
       base64 (~> 0.1.1)
       json (~> 2.5)
       money (~> 6.13)
diff --git a/README.md b/README.md
index 61117a1..9982c6a 100644
--- a/README.md
+++ b/README.md
@@ -69,6 +69,30 @@ class PaymentsController < ApplicationController
 end
 ```
 
+## You can add more params:
+
+```ruby
+# app/controllers/payments_controller.rb
+class PaymentsController < ApplicationController
+  def create
+    payment = MonopayRuby::Invoices::AdvancedInvoice.new(
+      "https://example.com",                    # your redirect url
+      "https://example.com/payments/webhook"    # your webhook url
+    )
+
+    if payment.create(amount, destination: nil, reference: nil, other_merchant_paymant_info_params: {}, other_params: {})
+      # your success code processing
+    else
+      # your error code processing
+      # flash[:error] = payment.error_messages
+    end
+  end
+end
+```
+
+other_merchant_paymant_info_params - details about additional merchant paymant info params for example - basketOrder to add information about bought itesm
+other_params - you can add any additional params you need at your project, for instance - googlePay for payment via google wallet
+
 ### Verify transaction
 
 ```ruby
diff --git a/lib/monopay-ruby/invoices/advanced_invoice.rb b/lib/monopay-ruby/invoices/advanced_invoice.rb
new file mode 100644
index 0000000..9136633
--- /dev/null
+++ b/lib/monopay-ruby/invoices/advanced_invoice.rb
@@ -0,0 +1,49 @@
+require_relative 'simple_invoice'
+
+module MonopayRuby
+  module Invoices
+    class AdvancedInvoice < MonopayRuby::Invoices::SimpleInvoice
+      attr_reader :merchant_payment_info, :other_params
+
+      def create(amount, destination: nil, reference: nil, other_merchant_paymant_info_params: {}, other_params: {})
+        @other_merchant_paymant_info_params = other_merchant_paymant_info_params
+        @other_params = other_params
+
+        super(amount, destination: destination, reference: reference)
+      end
+
+      # Request body required for Monobank API
+      #
+      # @return [Hash] request body
+      def request_body
+        # TODO: add "ccy" and another missing params
+        # TODO: remove nil valued params
+        request_body = {
+          amount: amount,
+          redirectUrl: redirect_url,
+          webHookUrl: webhook_url,
+          merchantPaymInfo: {
+            reference: reference,
+            destination: destination
+          }
+        }
+
+        request_body[:merchantPaymInfo].merge!(merchant_paymant_info) # add additional merchant_payment_info params if they are present
+        request_body.merge!(other_params)                             # add additional params if they are present
+
+        # TODO: add sum params into present additional params
+        if request_body[:merchantPaymInfo].has_key?(:basketOrder)
+          request_body[:merchantPaymInfo][:basketOrder].first[:sum] = convert_to_cents(amount)
+        elsif request_body.has_key?(:items)
+          request_body[:items].first[:sum] = convert_to_cents(amount)
+        end
+      end
+    end
+  end
+
+  private
+
+  def sum_param_into_basket
+    request_body[:merchantPaymInfo][:basketOrder][:qty] * amount
+  end
+end
diff --git a/lib/monopay-ruby/invoices/simple_invoice.rb b/lib/monopay-ruby/invoices/simple_invoice.rb
index 9d6cf8a..7a8b302 100644
--- a/lib/monopay-ruby/invoices/simple_invoice.rb
+++ b/lib/monopay-ruby/invoices/simple_invoice.rb
@@ -53,8 +53,6 @@ def create(amount, destination: nil, reference: nil)
         end
       end
 
-      private
-
       # Request body required for Monobank API
       #
       # @return [Hash] request body
diff --git a/lib/monopay-ruby/version.rb b/lib/monopay-ruby/version.rb
index e55885d..68dab9d 100644
--- a/lib/monopay-ruby/version.rb
+++ b/lib/monopay-ruby/version.rb
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module MonopayRuby
-  VERSION = "1.0.0"
+  VERSION = "1.1.0"
 end
diff --git a/spec/lib/invoices/advanced_invoice_spec.rb b/spec/lib/invoices/advanced_invoice_spec.rb
new file mode 100644
index 0000000..39e4bd2
--- /dev/null
+++ b/spec/lib/invoices/advanced_invoice_spec.rb
@@ -0,0 +1,53 @@
+# frozen_string_literal: true
+
+RSpec.describe MonopayRuby::Invoices::AdvancedInvoice do
+  describe "#new" do
+    let!(:redirect_url) { "https://redirect.example.com" }
+    let!(:webhook_url) { "https://webhook.example.com" }
+
+    context "with keyword parameters" do
+      subject { described_class.new(redirect_url: redirect_url, webhook_url: webhook_url) }
+
+      it "initializes with correct redirect_url" do
+        expect(subject.redirect_url).to eq(redirect_url)
+      end
+
+      it "initializes with correct webhook_url" do
+        expect(subject.webhook_url).to eq(webhook_url)
+      end
+    end
+
+    context "without keyword parameters" do
+      subject { described_class.new(redirect_url, webhook_url) }
+
+      it "raises an ArgumentError" do
+        expect { subject }.to raise_error(ArgumentError)
+      end
+    end
+
+    context "without parameters" do
+      subject { described_class.new }
+
+      it { is_expected.to be_a(described_class) }
+    end
+  end
+
+  describe "#create" do
+    context "when request is successful" do
+      let(:simple_invoice_instance) { described_class.new }
+      let(:invoice_id) { "p2_9ZgpZVsl3" }
+      let(:page_url) { "https://pay.mbnk.biz/p2_9ZgpZVsl3" }
+      let(:basket_order) { { name: "product", qty: 1 } }
+      let(:other_params) { { ccy: 9 } }
+      let(:response_example) { { "invoiceId": invoice_id, "pageUrl": page_url } }
+
+      before do
+        allow(RestClient).to receive(:post).and_return(double(body: response_example.to_json))
+      end
+
+      it "returns true" do
+        expect(simple_invoice_instance.create(2000, basket_order: basket_order, other_params: other_params)).to be_truthy
+      end
+    end
+  end
+end
diff --git a/spec/lib/invoices/simple_invoice_spec.rb b/spec/lib/invoices/simple_invoice_spec.rb
index 676c5e4..1157095 100644
--- a/spec/lib/invoices/simple_invoice_spec.rb
+++ b/spec/lib/invoices/simple_invoice_spec.rb
@@ -71,7 +71,13 @@
     context "when request is failed" do
       context "with missing token" do
         # move this code to shared example or mb shared context
-        let(:missing_x_token_server_message) { { "errorDescription" => "Missing required header 'X-Token'" } }
+        let(:missing_x_token_server_message) {
+          {
+            "errCode" => "BAD_REQUEST",
+            "errText" => "Missing required header 'X-Token'",
+            "errorDescription" => "Missing required header 'X-Token'"
+          }
+        }
         let(:error_code) { "400 Bad Request" }
         let(:missing_x_token_header_error_message) do
           [error_code, missing_x_token_server_message].join(", ")