Problems with precompiled script plugins

Hi colleagues,
I’ve found this thread looking for a way to share build logic common for all subprojects. I read the User Guide (Sharing Build Logic between Subprojects) and it seemed clear and simple. I created shared.gradle.kts in buildSrc directory, put there common declatations on repositories, plugins and dependencies, and I expected it just to work the same way as before. But I got multiple error messages, saying gradle cannot resolve references in shared.gradle.kts - so it cannot recognise such names as testImplementation, libs (version catalog), java, etc.
Can you please explain in some simple words how it is supposed to work? I am absolutely lost with this.

Please do not post questions to totally unrelated threads.
That thread was specifically about using version catalogs in precompiled script plugins.

Regarding your question, the simple words are what you linked to.
If you don’t understand something, or have concrete problems you need help with,
you need to share more then no details at all like you just did.
Noone can guess what you put where and which concrete errors you get.