Thanks for the mention.
I messed around a bit longer and I think I got it working w/o Patreon now.
Can you or someone else test this and confirm? It worked for me.
Download my attachment and extract the .pak file that's inside the zip to the
\X64\WindowsNoEditor\GrowthRPG\Content\Paks\ folder. So now you should have 2 pak files total in that folder. Then simply start the game.
This file should work for future versions too, unless the author decides to implement the Patreon checks another way.
Cheers,