I finally managed to install the srajawwal09 version of Ram Cleanup on Android 11. The application just needed to be resigned. I'd never done it before, so thanks @ThisIs50 for its precious help . The application works on my S20+ but I think it should work on all Android 11.
https://userupload.net/ohclawph2q2r

Thank you great, it work on S20 Android 11 too

I finally managed to install the srajawwal09 version of Ram Cleanup on Android 11. The application just needed to be resigned.
I'd never done it before, so thanks @ThisIs50 for its precious help The application works on my S20+ but I think it should work
on all Android 11. https://userupload.net/ohclawph2q2r

For those who want to know how solve this installation problem of this app and several other applications with Android 11 on the forum or for future releases if the problem persists.. it's very simple I used MT Manager
viewtopic.php?f=438&t=3997511&hilit=MT+manager
Download ,install & open it. Click on the .apk > Function > APK Sign > Scheme - v1+v2 and that's it the Apk is resigned and work.

I warm people that my malwarebytes not like this application at all Probably a false positive but I didn't allow
the application to manage phone call management, the application worked perfectly without and I deleted the data
and uninstalled the app after use it (my opinion)

Perfectly functional on Google Pixel 2 XL!

Thank you so much for insisting on making it A11 compliant and to ThisIs50 for their help in making it possible.