Installing
2. Enabling Extras Repo
How to Add Debian Extras Repos Preserving System Stability
Follow instructions to Enable Debian Experimental Main, Contrib and Non Free Repo.
3. Installing
Then to Install GTX 1660 SUPER Driver on Debian
Simply run:sudo apt install nvidia-driver nvidia-settings
If Got “User is Not in Sudoers file” then see: How to Enable sudo
And Possibly to Configure the X Server after Setup run:nvidia-xconfig