Setup openvpn and configure ovenvpn client in ATA

HI,
I have a VOIP ATA that uses openvpn. see attached openvpn configuration page of the device.
I want a freelancer to setup my linux for openvpn as what works for this device and then successfully have the ATA (device / client) configured for the same openvpn server.
Attached is the introduction file about the device and its manual.

At the end (after device successfully connecting to openvpn server) of the project, I will need to know all about how to setup the openvpn server and client via a video or a document.