@generix
OK, looks like that worked. The OS says that now it uses “GeForce RTX 3070 Laptop GPU/PCIe/SSE2”
Here is the output of the above commands:
$ sudo dpkg -l |grep nvidia-prime
ii nvidia-prime 0.8.15.3~0.20.04.1 all Tools to enable NVIDIA's Prime
$ sudo dpkg -l |grep ubuntu-drivers-common
ii ubuntu-drivers-common 1:0.8.6.5~0.20.04.1 amd64 Detect and install additional Ubuntu driver packages