[rmrector]

3) if I want to generate nfo files for future use, I export the movie library. When kody asks me for downloading artist, fanarts files and overwrite current files, What do I have to do?
     do these choices interfere in any way with a good final result (a clean movie folder organization and a right number of files with the choosen naming convention) or not?

Don't export artwork from Kodi at all. Artwork Beef's settings have nothing to do with Kodi's export. Configure AB to download artwork, then run Add missing artwork for items, and it should download them next to your media. If not I need more information to help you, look at the bottom of the first post to find out what that is.
 

But now every time i get a fault message, that the api for fanart and theaudiodb.com Project api key isn't installed correct. … what can it be?

See the documentation on “Invalid project API key”. Remove all "project" API settings.
 

But AB can’t find the artwork locally since it’s not local. Is there a solution to allow AB to get the art I already have? Thank you!

Nope. It requires local files.
 

call AB to download just one artwork type for tv shows.

@rmrector , if this is not possible today, would you consider adding it in the future? Thanks for considering my request.

Nope. That's a silly function; users decide which art types they want in Artwork Beef's configuration, not whatever random buttons may be scattered around.



@SMB-IL, @Starmanrf, @Jondar

I cannot reproduce. I need more information to help you, see the bottom of the first post for details. Since you've all tied for giving me as little information as possible (and spent some effort complaining and downgrading and anything but reading the first post), let's have a little competition: Which of you can give me the MOST amount of information on your problem! And give the debug context item "AB: Log debug info" a try while debug logging is enabled.