Resize the APFS container (encrypted) – Ask Different

I'm having trouble "allocating" some free space on the "file partition" to the volume that contains the system files: an encrypted APFS container. I would like to do this because I am no longer able to update a large app from the App Store. I have already read a few articles dealing with the problem of resizing APFS containers but they still don't answer my question (or maybe I didn't clearly understand the idea). I use a MacbookAir under Catalina.

I have put some screenshots which can give more useful information.

Reduce this volume to 90 GBReduce this volume to 90 GB
Increase container capacity to 160 GBIncrease container capacity to 160 GB
diskutil listdiskutil list

Thanks for your help.