Your card seems to work with Nvidia 390 series driver and no later. You can verify that too with program nvidia-driver-supported-brances (if you have package nvidia-inst installed).
You may want to try nvidia-inst as well, e.g. like this:
nvidia-inst -t --series 390 --prime
It will not install anything, but should recommend the packages to install.
Though I’m not sure (since I cannot test it) if those recommended packages are enough to get it working, but should be a starting point anyway.