Hi there,
Cloudflare does not allow video stream outside Cloudflare Stream or Stream delivery:
Having said this, it would not output a 522. A 522 means your origin is not responding. Make sure your networking gear has the port open, is accepting requests for Cloudflare IP addresses, and it’s directing it to the correct IP on your internal network.
Alternatively consider using cloudflared as it will not require you to open ports on your router nor use a reverse proxy like nginx, and you’ll have a clear view of you tunnel health right on your ZT dashboard.
Take care.