I'm facing now issue that , I have FCM topic and this topic has many subscriber I want the admin removes user from topic not this user unsubscribe by him self.
You can use firebase-admin. You just need to get the users' FCM tokens into an array then pass in the array of user tokens you would like to
// These registration tokens come from the client FCM SDKs.
var registrationTokens = [
'YOUR_REGISTRATION_TOKEN_1',
// ...
'YOUR_REGISTRATION_TOKEN_n'
];
// Unsubscribe the devices corresponding to the registration tokens from
// the topic.
admin.messaging().unsubscribeFromTopic(registrationTokens, topic)
.then(function(response) {
// See the MessagingTopicManagementResponse reference documentation
// for the contents of response.
console.log('Successfully unsubscribed from topic:', response);
})
.catch(function(error) {
console.log('Error unsubscribing from topic:', error);
});
where the registrationTokens are the user tokens and topic is just String of the topic you would want to unscribe the user from.