Thanks Kino atlet,
exactly, the option already exists for sending GPS data to AVL or TAVL server. However, it does not exist for sending GPS data to an HTTP(S) server.
The data send to the AVL / TAVL server is in proprietary binary format, the data sent to the HTTP(S) server is clear text NMEA sentences, which is easier to parse.
If Teltonika cannot or does not want to implement this feature for the HTTP(S) server, I will have to write a decoder for the proprietary format.