You installed a flatpak GIMP, which is sandboxed. It will not have the same file paths, so I do not believe PhotoGIMP will work on it.
This is a user directory configuration file for gimp that saves your personal settings for GIMP. It is created and populated once you install GIMP through the standard APT format.
I had made the assumption you had GIMP installed already. Which.... I should know better by now than to do.
I recommend removing the flatpak, then installing GIMP
sudo apt update && sudo apt install gimp
Then you should be able to move the files without trouble.
In that case, wee are deviating from your original goal.
If you want to use PhotoGIMP, I recommend removing the Flatpak version and installing the standard format version, then moving the files as defined above.
Flatpaks keep their files in a different place from standard.
Gimp User settings and where you are looking to move your files into for PhotoGIMP are in ~/.config/GIMP/2.10/
This is in your home directory - and the system configuration files in home are "hidden" - tap ctl+h to toggle whether hidden or shown.
This is also selectable in the file manager preferences.
The system wide GIMP files that the program runs on are located in root. /usr/share/gimp
The contents of the photoGIMP folder do not share any common file or folder names, so I reckon it's just to copy paste EVERYTHING into the 2.10 directory,
and see what happens.
So.. copy/pasted the contents of photoGIMP into GIMP/2.10
opened GIMP, and there is no change.
Connot find any newly installed application called photoGIMP.
No instructions on what to do once the files are merged.
The way photoGIMP is presented is a very odd way of doing things.
I suspect that you are not changing directory into the PhotoGIMP folder, first.
cd PhotoGIMP
After you have changed directory, your terminal will show you at the prompt what directory you are in.
Then run cp -r .var/app/org.gimp.GIMP/config/GIMP/2.10/* ~/.config/GIMP/2.10/
It works. I just tested it by running it. Now, I will delete the changes and restore my back up.
It looks much more like Photoshop layoutwise, although the tool bar has less tools.
The downside is that it still functions the same as vanilla GIMP.
I still cannot select and edit the text in PSD files, nor XCF files.
The text tool looks like a cross-hair + a capital serif letter I below it.
neither the cross-hair or I mark actually select anything.
The text tool in Photoshop is so straight forward - any child can use it.
I had hoped photoGIMP would be more than just a modified shell.
Also, I find that exporting a file rather than save as, still does not show any list of file extensions. Only PNG was shown as an export option.
Surely GIMP is able to edit text -- but how this is done is a well kept secret.
All the tools in Photoshop function intuitively exactly as one would expect them to do. But in GIMP it's a mystery how anything works.
In Photoshop, unrasterised text can only be saved as a text layer.
Text is only rasterised by selecting "rasterise layer" from the menu.
But now I see that all the text layers are auto-rasterised on opening the PSD. So there is no possibility of editing text in a PSD.
Only recreating text after deleting rasterised text. (Wacky)
I honestly don't see any extension file type options in any menu.
I've looked everywhere. Why not a simple dropdown list as in Photoshop?
