I'm not sure how easy or difficult it is to build a STUN or TURN server from scratch on our own since I haven't tried it.
For my previous WebRTC project, I used an open source TURN/STUN implementation called COTURN and hosted it on a DigitalOcean instance.
Also, there are multiple publicly available STUN servers that you can use.
tinyurl.com/y3345yop (All STUN servers in this list may not be live)
The task of STUN seems simple, which is telling you your IP, this is why I asked about the complexity of building one.
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