Photos Library not appearing in iMovie

Hello!

I can't access my Photo Library (mac Photos app) in iMovie. The Photos option is not available on the side bar to access the Photo library. I have tried doing changing the preference and create new library and used it my system preference but it didn't work. I've tried checking online and youtube and tried all but nothing worked. I wonder what's happening and what should I do?

I hope someone can help. I'm using MacBook, latest one I bought last year.

Thank you!