What to put under polygel?

Hey, I'm doing my nails at home and till now I've been doing my nails with builder gel or biab, for lengthening I use glue on tips and nail forms.

I just bought a hybrid polyacryl, and I'm curious on what are y'all putting under it. I'm using dehydrator and primer, though I'm not sure to put a rubber base or just base coat, maybe a fiber gel for extra longevity. I could use some advice! Thank you so much to anyone responding.