Thanks Shadrack,
In the webinar video I mentioned above, Tomas, the presentator, mentioned that Teltonika is going to provide an own VPN client which would be automatically configured. Similar to the Teltonika devices.
I got an answer in the Youtube question I asked as well. Seems Teltokika is still developing that client.
Anyway, I am happy to use the OpenVPN Connect client until then.
Dan