If your device used to work as Xexun TK103-2 before then please specify in the units settings:
Device Category - Hardware
Device Type - Xexun TK103-2
After that, you can find in the unit menu - Settings - Common settings port and server on which you need to configure the tracker.
If your tracker supports DNS server format, then configure the tracker to:
Server Host - 12741.flespi.gw
Port - 26731
If your tracker only supports the IP server format (to see it, click the IP button next to the server value), configure the tracker to:
Server Host - 184.108.40.206
Port – 26731
You can read more information here https://forum.gps-trace.com/d/340-how-to-connect-trackers-of-types-gt06-gt06n-gt02-gt02a-tk110-and-etc
Concerning the IMEI you can try to identify your tracker on id.wialon.net as one of the devices Xexun, Coban, Concox.
If your tracker is determined, take a screenshot, write down the name of the model of the tracker and the identified ID (may coincide with the IMEI, may be part of it with zero or without).
After that, return to the application in the unit settings (unit menu - Settings - Common Settings), specify the determined model and ID. After that, configure the tracker on the defined server and port.