Galène is a video conferencing server that is easy to deploy and requires few server resources. https://galene.org/

For Yunohost, you will need to assign it a domain name or subdomain, for example visio.err404.numericore.com
If you do not have a public IPv6 address to assign to this machine, it will be very difficult to provide a real video conferencing service. (It won't work for everyone, and it's best not to assign a public IPv4 address until you have a working TURN service.)

In my Galène, I wanted to be the administrator (op), but I also wanted visitors to have some rights to present their screen or other things, so I added the line ‘’“presenter”: [{}],‘’ before the description, and I restarted the Galène service.
Here is what my public.json file looks like:

{
   "users":{
      "err404":{
         "permissions":"op",
         "password":{"type":"pbkdf2","hash":"sha-256","key":"xxxxxxxxxxxxxxxxxx","salt":"yyyyyyyyyyyyyyyy","iterations":4096}
         }
      },
      "presenter": [{}],
      "description":"name or password are optionals",
      "public":true,
      "allow-recording":true,
      "auto-subgroups":true
}