Video-conferencing is not really EPiServer-related functionality. But EPiServer doesn't stop you from implementing it, either.
What you need to do is find a video conference vendor/product that can be embedded or iframed on a webpage.
While I don't have first hand experience with any in particular, a quick Google search leads me to e.g. appear.in, meetings.io, VSee etc.
These products probably aren't free (requires license), but I doubt you'll find a video conference module that's free for commercial use anyway.