mitchy1690 - that old Zgemma might not have the juice to deal with the OpenVPN encrytion. However, H7 and H9 series do!
Jw2000uk - one must have all the parts (keys and credentials) included, as I wrote earlier, so one must deal with auth, cert and .ovpn files properly!
All the files do NOT have to be in the same folder, if you do things properly.... Put it to NO!
Default DNS, as I demonstrated: 1.1.1.1
Surfshark has both keys in .ovpn file, other providers do not, as far as I can tell. So, in that folder, it seems to me, one must have to have at least another file, which contains the other key.
Whereas your login details (username and password) go to plugin.py file, as I described....