it literally only works on a Google pixel phone. I don't know if there is much you can do in an iPhone. you can jailbreak it but that brings in other security vulnerabilities. grapheneOS is designed specifically for the inner workings of a pixel.

I had an iPhone since the first iPhone. I'll never look back now. I absolutely love my Pixel. and although graphene can be a little quirky in some ways, you sacrifice a few things for the benefit of your privacy, it's amazing