How to install Fn button switch on macbook?

Question

macOS

Good day to all. I am a new macOS user. I recently bought a MacBook Pro 20 years old with a touchbar.
I have a frequent need to switch between the touchbar and function buttons.
On a working HP laptop, it is possible to turn on Fn-lock, that is, it works like a CAPS-LOCK switch.
The closest functionality is given by the FNable program, which switches Fn when held for 3 seconds.
But it works crookedly on BigSur and crashes periodically.
Ideally, I want to switch between modes with a single press of the Fn button

Answer 1

and can nafig pull old habits and start using what the system provides?
when you press fn, the entire touchbar turns into function keys. what else does?
upd:
https://fluorapp.net/
https://www.techmasterdesign.com/fnswitch/
https://github.com/jakubroztocil/macos-fn-toggle

Answer 2

Try the bettertouchtool and karabiner applications, in previous macbooks (before replacing the fn with a touch) this could be done with their help.