Recover offline files from OneNote

Job ID: 31664131

Budget: $10 – $30 USD

Hello everyone.
I will explain from the very beginning what happened to me and what kind of help I need.

PLEASE READ CAREFULLY.

I tried to install Mac Big Sur update on my Mac Mojave (Macbook Air 2019) but it got stuck in the middle (black screen already, black screen trying to update but nothing). I waited for about 6h to see if the updated was completed, but no, nothing. So I tried to find other ways to do it or to go back to Mac Mojave.

I read online that it was possible to go back my installing Mac Mojave on Safety Mode (commad + shift + R + option), so I did it.
Turns out, it looks like I'm now a new user and all my previous files, apps, everything (picture1, attached), including the app from Microsoft OneNote (onenote1, attached).
When I opened, it shows ONLY my online files, my online notebooks.

I tried everything to recover my offline files, everything at all, with no success.

It's not saved on my OneDrive, at least not in my personal one drive, because I searched it all over.

And guess what: I have a VERY IMPORTANT test in ONE WEEK and my entire notebook is lost.

So, please, can anyone HELP me to RETRIEVE MY OFFLINE NOTEBOOK??

I will pay whoever help me to get my files from OneNote back, doesn't matter how.

Attention:
1) There is a chance those files are saved on my OneDrive for Business - but I can't access now because I'm on vacation, so the company blocks everything. So, whoever takes that project, must be able to pass it through.