I’ve seen Big Blue Button in other orgs but haven’t used it myself, it’s gotten good feedback. Discord works very well as a communication platform for me and other members of the party seem to have adapted well.
Another option could be to host jitsi. I think some non-profit organizations set it in a way that a member must create each online meeting as organizer. Then the video/audio chat is not spammed because a member is always present to moderate. Non-members can join the chat via shared link.