Hello.
You need to use SMS command "readio" and then corresponding AVL ID.
Parameters and their respective AVL IDs can be found here: https://wiki.teltonika-gps.com/view/FMB640_Teltonika_Data_Sending_Parameters_ID
For example:
Fuel level has AVL ID of 87, so the command should be like this:
<login> <password> readio 87
if You have no login or password set, just leave 2 blank spaces before the command: " readio 87"
Best Regards