title: How to convert a FCM token to APNS token?
body: <p>We consider migrating from Firebase Cloud Messaging to build our own push engine. We need to migrate the users converting FCM tokens to get the raw APNS token. How can that be done? </p>
  
  <p>I can only find a procedure to convert APNS to FCM tokens. <a href="https://developers.google.com/instance-id/reference/server#create_registration_tokens_for_apns_tokens" rel="noreferrer">https://developers.google.com/instance-id/reference/server#create_registration_tokens_for_apns_tokens</a></p>
  
  <p>Any way to decode the FCM tokens?</p>