Why this javascript custom search not work?

[woshichuanqilz]

I the custom search engine. I have the code :

t: javascript:\ alert('hello'); JavaScript
m: javascript:\ (async () => { try { await navigator.clipboard.writeText(`[${document.title}](${location.href})`); console.log('Markdown link copied to clipboard.'); } catch (err) { console.error('Failed to copy markdown link to clipboard:', err); } })(); JavaScript

This code works fine in dev console.
Use m to copy the current url in markdown mode. But nothing happens when I trigger it.
I can trigger simple code. Like alert('hello')

[gdh1995]

the spaces must be encoded (%20)or escaped (like the one in javascript:\ alert).

or save it as a bookmark and then map xxx openBookmark title="the-exact-title-of-a-target-bookmark"