Not mentioned there for some reason but Mozilla’s VPN is Mullvad VPN.
This page says it is from cloudflare. so it may be cloudflare WARP.
“Firefox Private Network browser protection uses a server provided by our partner Cloudflare, who collects a limited amount of data and deletes it permanently after 24 hours.”
There are obviously two different pages you are referring to:
- The Firefox Private Network browser addon; uses Cloudflare as a service provider
- The Firefox Private Network VPN service; uses Mullvad as a service provider
Both browser addon and VPN service are only available for US-based users at the moment.