“Gimp is good but i miss the heal patch” …not really.
Resynthesize is a heal selection plugin you can add to Gimp. With many software store manager like the one from Linux Mint all you have to do is simply to add the additional components in the software page
Otherwise you can download it from github and add it to your plugin folder following this guide
https://www.arkthinker.com/edit-image/remove-the-watermark-with-gimp/
https://github.com/bootchk/resynthesizer
once installed you can find it in Filters> Enhance > Heal section
More Gimp plugins
https://beebom.com/best-gimp-plugins/
https://www.makeuseof.com/tag/install-gimp-plugins/
Which version of the plugin did you install. There’s a whole bunch of them when you type flatpak install gimp. The resynthesizer version that works with gimp3 flatpak is number 20 in my screenshot. The one that has the 3