KauriGuttunen Hello.
First can you clarify what tracker model you mean: Teltonika FM1110 or Teltonika FM1100.
Then if your tracker supports the IP server format configure the tracker to:
Server Host - 193.193.165.37
Port - 20856
You can also try to configure your tracker to DNS server format (to see it, click the DNS button next to the server value):
Server Host - 11249.flespi.gw
Port - 20856
In both cases the port is 20856, can you explain why you chose the value 26759 before?