Add a custom validation

[plamber]

Hello,
we are using the fields component in formik to register custom fields.

<Field
        name="richtextField"
        label="Textarea that allows HTML"
        required
        allowHtml={true}
        component={RichTextarea}
      />

I am looking for a way to register a custom validation function that is applied to this control. The validation function must be registered in our "RichTextarea" component and ensure that specific rules are always verified.

Do you have some examples how we could achieve this goal?

Thank you,
Patrick