I have been using the AVA app to caption in Zoom and it is working well. Essentially AVA joins the Zoom meeting via telephone to caption all of the participants in the Zoom meeting. If you want a free live demo of this, sign yourself up on this calendar for a 30 minute slot:
Once you get AVA permission to use the AVA app in Zoom, I did a 13 min video on how to set it up. Just respond to this post, if you want to see it and I will send it to you.