Cannot access Final Cut Pro x (paid version) after updating OS on MacBook Pro mid 2015

Hi,

I have been using the MacBook Pro (Retina, mid 2015) for Logic Pro x & Final Cut Pro x (both of which were legally purchased from the App Store in 2018). In order to avoid any glitches, I was avoiding updating the OS for a long time, preferring to work in an environment I was familiar with. Recently (in a momentary lapse of reason), I updated the OS to the latest compatible version (Mac OS 12 Monterey). Unfortunately, I find I cannot access Final Cut Pro x at all - I cannot open any projects or even the app itself. I have tried the following -

Uninstalling FCPx and trying to reinstall it from the 'purchased apps' section in the App Store

The pop up message reads "This application requires macOS 15.6 or later (which is not compatible with my laptop)

This is very frustrating - I have a mint condition, very sparingly used MacBook Pro, and have paid for FCPx.

Why does Apple not have the provision to download an older version of FCPx that is compatible with my laptop?? After logging in to my Apple account, my devices are accurately identified and displayed - when the system was able to immediately suggest the latest compatible OS for my laptop, why is there no download option for the compatible versions of the apps that I have paid for??

I can't be dishing out close to INR 3,00,000 for a new laptop, when mine is in mint condition and works perfectly.

Please help me out with this. All info, suggestions, work-arounds welcome.

Thanks in advance.

Apple support - please help!!