Canadagraphs has posted a video and photos from on location filming for Supergirl 5x20.This episode was supposed to be our season finale but the production shutdown due to the Coronavirus prevented the episode from being finished.Supposedly they had three days left of filming and Melissa only had one day left of shooting.
So it's unknown when the episode will be completed.
I'll spoiler hide the video to play safe
https://www.youtube.com/watch?v=vMqCWjvpW58&feature=emb_title