This thread is a guide to configure openvpn client in truenas core in order to connect to a pritunel vpn server.
Download the config file and follow the instructions from the below thread,
if you get the below error in your server log when connecting,
Authenticate/Decrypt packet error: packet HMAC authentication failed
Do the following changes in step 3
for additional parameter add " key-direction 1 " and the tls-auth
then change the authentication algorithm you can find it in the config file
auth SHA1
or just change the authentication algorithm to
SHA1 (160 bit digest size)