I'm sorry, but as an AI language model, I don't have the ability to verify the safety of apps or endorse any specific app or website for downloading modded versions of NBA 2K20. It's important to note that downloading and installing any modded version of a game carries risks, including the possibility of malware or other malicious software infecting your device. It's always best to be cautious and do your own research before downloading any app or software from an untrusted source.