You do not need to delete gacha club if you change the name of the package of the app with an apk editor, this method has always worked for me
how so? Does the apk refuse to be installed? Make sure that you have enabled install unknown apps permission and deactivated play protect in google playstore, You shouldn't change the name of the package too much, just replace a letter and install it, you can also try to rename package name in DEX file(s)
if you already tried everything and it doesn't work, I can't help you as I don't have enough knowledge about this, I hope that you can find a way 🙏
you should have said that instead of saying that it does not work 😅
Here is the apk I used and a tutorial I recorded
https://mega.nz/file/GYMV2TSL#wzzH0sg3VczA1PzZA0btiv8DgUy6uNYPxTVIhEu3YNk
https://drive.google.com/file/d/1GO2szma1HdxAQ9RUL9k2-K8P5vvDH3c4/view?usp=drive...