How to handle internal Nvidia GPU plus gGPU in the same System


I have a somewhat strange setup: my notebook already has an internal GPU (RTX 3000), but i also have a Thunderbolt connected eGPU (RTX 3070). Don’t judge me :D It was an accident, i never thought i would need more than the RTX 3000. Until i noticed i was wrong.
Anyway, it works. Technically. Normal prime without the eGPU works fine, connecting the eGPU works fine and technically, even the eGPU works. If i can find some game which lets me choose which GPU to use. Most don’t.
Just about every Game just uses “the first one”, which happens to be the internal Nvidia. So, is there a way to force games to use a specific GPU (out of multiple of the same kind)? Or at least change the order of the GPUs?
Would be awesome :)