I am using FCM. Stored refresh token in text file. Fetch that tokens from file and send push notification.
When I send notification , I got following response
MulticastResult(multicast_id=7511693072672067374,total=3,success=2,failure=1,canonical_ids=0,results: [[ errorCode=NotRegistered ], [ messageId=0:1488863605846176%8fe03d2ef9fd7ecd ], [ messageId=0:1488863605846740%8fe03d2ef9fd7ecd ]]
Now, I want to know which refresh token is get errorcode like 'NotRegistered ' to remove it from text file. I want to send notification to almost 2000+ users