adsense in header

Please check documentation for page-specific header code:

https://adinserter.pro/documentation/plugin-settings#page-specific-header-footer

thank you but i found that very complicated !!!
Is there no easier way or a clearer explanation of the matter?

Well, all you have to do is to specify what to insert and where to insert.

The easiest way to disable insertion in one post is by black-listing it:
https://adinserter.pro/documentation/black-and-white-lists

Have you managed to configure insertion?