For anybody wanting to utilize AirVPN via a Docker VPN client container, Gluetun has now added AirVPN support for both OpenVPN and WireGuard connections. The container itself is very lightweight and fast. https://github.com/qdm12/gluetun
Here's an example of a Portainer Stack using Gluetun as the path to the Internet for a Firefox container:
version: '3.7'
services:
gluetun:
image: qmcgaw/gluetun:latest
container_name: gluetun
cap_add:
- NET_ADMIN