Hi Daniel,
I´ve been googling hard to find a solution that works for me.
As Im no IT guy its a bit complicated to get prepaid VPN service as Client to work on IPFire. I wish the devs make the VPN client setup as easy as on my ASUS router or OpenWRT or iGL.Net devices…
However This is a solution that helped me:
Download and open the provided zip. There is a pdf with step by step instructions.
If you are on Windows or MacOs I strongly recommend Total Commander with SFTP Client plug-in to access and easy edit ipfire config files via TC.
Hope this help
C.