I'll move this topic to where it belongs later ...
We do not ask for money here, we share our knowledge selflessly

When you download new apps, legally, from the store, and install them, they are integrated into the system. System functions also work then, mostly. Actually, the mentioned applications are intended for such cases
iGO, and especially the "Forum editions", is still a much older version of the software. It can be integrated with the system, but there can be problems

Until Android 13, it doesn't matter which iGO version you use. The one you like the most.

I see that even though you are a senior member, you have missed a lot
Skins are not installed like WinCE editions used to be. The skin is now not a separate plugin.
Additionally, Primo skins cannot be applied to NextGen releases. So all these skins you have are not usable
The installation comes down to deleting the content of UX folder and other files that go with the skin if there are any (data.zip, branding, etc), and replace them with the ones that came in the skin package
There are instructions in each of the skin themes, it has been discussed many times, you just had to browse more carefully

The only thing you still have to pay attention to is that the iGO folder is correctly located (in the device's internal memory), sys file properly adjusted especially with skin replacement, that the app has been granted the necessary permissions and that's it.

All other sufficiently detailed instructions exist on the Forum, starting from this:
[Only registered and activated users can see links. ]