The kernel that comes with ubuntu 20.04 is too old to drive your AMD gpu. Either install a 5.9 kernel
https://forums.developer.nvidia.com/t/nvidia-gtx-1650-lenovo-ideapad-3-ryzen-4600h-ubuntu-18-04-hdmi-screen-not-detected/161703/7?u=generix
or upgrade to kubuntu 20.10.
You should then be able to use the nvidia gpu in offload mode.
If you also want to use external monitors, some tweaks might be necessary for 20.04:
https://forums.developer.nvidia.com/t/nvidia-xconfig-doesnt-do-what-i-want-it-to-nor-does-nvidia-settings/107883/7?u=generix