I helped a friend who is an academic with some research. At the end of the project I find myself with a few months remaining on the small VPS we used (Clawcloud 2CPU 4GB/20GB. Debian). Could I use it for a modest VPN? If yes, what should I run on the server and how do I configure the router (BT HH5a)? I did a preliminary search on the matter but came up empty.
Configure WireGuard on the VPS, set it up as a "server" and the router as WireGuard client.
WireGuard Server Setup Guide
WireGuard Client Setup Guide
The Server setup guide is for OpenWRT but has a reference for setting up WireGuard on a VPS (I am running my VPS on an Oracle Cloud free VPS)
Thank you for taking the time to reply, that is very helpful.
There are about 1000 guides on how to bring up wg server on VPS.
If the VPS lets you load your own OS you can run OpenWrt there.