Here is the issue:
Your GPU is now completely obsolete. Nvidia had already ended all driver support for all Fermi GPUs such as yours back in 2018. The very last driver version ever released for these Fermi GPUs was version 391.35, released at the end of March 2018. Premiere Pro 2020 now requires driver version 430.86 or higher, which is now completely incompatible with your GPU, just for Premiere Pro to work properly. Nvidia will never release another driver version for your GPU. Never.
Sorry.
What's more, that GT 620 is now almost completely useless for GPU acceleration {the retail versions had only 96 CUDA cores, and some OEM versions were even worse with only 48 CUDA cores, and a memory throughput that's far below that of system RAM (only 14 GB/s) - compared to the over 1,000 CUDA cores and the 200+ GB/s memory throughput that we're now recommending for newer versions of Premiere Pro}, and none of the Fermi GPUs support the new GPU-based hardware H.264/HEVC encoding feature that's included with Premiere Pro 14.2 or higher. In fact, none of the Fermi GPUs have a hardware encoder at all.
As a result of all that, I'd suggest completely replacing that low-end Fermi relic with a new Turing GTX 1650.