If you purchased and installed from Google Play the Pro version,
you should launch only the Pro if use the proper Pro launch icon.
That is already answered above:
Google Play only allows you to install the latest version of applications.
What other providers? Apps are supported only via Google Play, everything else is illegal!
As mentioned above, you can uninstall all Kurviger apps, go to Pro version and reinstall it.
Google Play Help has instructions to find previously purchased or downloaded apps:
“You can use apps you bought on Google Play on any Android device without paying again. However, each device must have the same Google Account on it.”
If you need help, please answer our questions and attach screenshots of what you install.
So community can understand what you’re doing and help more.