In case anybody has this issue.
This page works perfectly and is very simple:
vpn
This is a little late, but if you still want to try surfshark with wg, it was pretty easy on 13 because you can get the config file from their site, rename it to wg0.conf and it would work. I have since moved to 14 due to hardware change and it doesn't work atm, (I don't have time to fiddle) and I don't have 13 installed to test if it's still the case.
Anyhoo, install the pkg wireguard-tools, and also wireguard-kmod if wg isn't in base (i don't remember, but I used that package before). Then go to surfsharks main website and login, it will take you to the Dashboard. On the left of that web page there is a Home menu, and then a VPN Menu under that. Click on that (VPN menu), then click on Manual setup.
From there you will get a new page saying Choose Protocol, with Wireguard, OpenVPN and IKEv2. Click on Wireguard to get to this -
From this Credentials tab, click on "I don't have a key pair" and it will generate them for you. You can save the keys to your account for later use (it will ask you to enter a name for them), but they will already be in the conf files that you will download, (you can double check once downloaded).
After generating the keys, go to the Locations tab. It is a list of their servers by Country and City. Choose the one/s you want, click on them and you will get a Pop-up with a Download Link at the bottom. The downloaded file will have a name with country code, and .conf extension, eg it-rom.conf for Italy-Rome. On 13 they worked as is, just rename the one you want to wg0.conf and copy it to /usr/local/etc/wireguard ( so it will be /usr/local/etc/wireguard/wg0.conf).
In /etc/rc.conf, have
wireguard_enable="YES"
wireguard_interface="wg0"
and then run (if wireguard service is running)
# wg-quick up wg0
That should be it, and it would work on 13 ( I had 13 till about a month ago). On 14 I haven't managed yet, as that last part returns an error, using base wg. (not bothered for now).
Edit: Ok, the problem was on Surfshark's side. The last line in the config files is an error atm and it is not including the full address of the Endpoint. Should be xx-xxx.prod.surfshark.com. (xx-xxx is country/city code). You can check the OpenVPN versions from the web pages mentioned above.
