We have pointed Teltonika FMB 920 but we are not able to get the correct ignition value,
Can you please specify your problem with more details. Don't you receive engine.ignition.status parameter? Do you receive the parameter but its value is wrong? How did you connect the wires of your device? Did you play around with the settings like "Ignition Detection Source"?
engine.ignition.status yes this value is giving wrong ( means always it is false ) only, We setup ignition source as Digital Input 1 We got something like we can find value in DIN? how do process that?
According to Teltonika manuals https://wiki.teltonika.lt/view/FMB920 Digital Input 1 is coming inside the tag 1; ignition state is coming inside the tag 239. If engine.igntion parameter is present then device reports it correctly. I suppose that you have some problems in wiring. Are you sure that you connected yellow pin to vehicle ignition as explained here https://wiki.teltonika.lt/view/FMB920_First_Start? Do you have another FMB920 devices connected? Do all of them report igntion with error?