Goseur7 It wouldn’t be possible for the Play Store to update a modified, non-genuine app.
It will not be possible to update an app with a different "signature".
I would underline this because sometimes you would fine the same developer signing differently the same app, or assigning them a different name using the same signing key.
By extension, this might overlap with your statement: if you installed a rough app it most probably have a different signature (unless the chain of trust is compromised) and cannot be updated via Play Store.
makki Just a way of installing and updating apps from their original source (Play Store) without having to use a Google account on my owner profile.
I had luck using APKUpdater.