How to meet several people w/ voice online for free

Need answer kinda fast. The things I thought would work don’t work.

What I need is for some unknown number of people (I’d estimate in the 20’s) to be able, tonight, to so to speak come in and out of a virtual conference room at will, where they will be able to hear me talking and at the very least see each other texting if not hearing each other speak.

Join.me only allows up to 10. Gotomeeting is not free. I originally thought Skype has this functionality but if so, I’m not seeing it–I can call multiple people but what I need is for multiple people to call me.

Is there a way to do this?

Okay, I think Discord will do the trick.