For the best Nvidia Optimus experience IMO go with an arch based distro, something like Endeavor OS, and install and configure Optimus Manager. It has a Hybrid Mode which makes it work much like it does on Windows, were you just launch a game and it uses the dedicated GPU. I like it better that way vs having to be switching modes manually.

Here’s a guide for it: https://discovery.endeavouros.com/nvidia/optimus-manager-for-nvidia/2021/03/