Do push notifications use 3rd party brokers?

Product Support
3

Sorry for rehashing this, but my searches lead me here and I’m not sure if its related.

Our /logs are filled with the:

Failed to send push notification : host: fcm.googleapis.com, #<Net::HTTPForbidden 403 Forbidden readbody=true> body: the key in the authorization header does not correspond to the sender ID used to subscribe this user. Please ensure you are using the correct sender ID and server Key from the Firebase console.

Backtrace 
webpush-1.1.0/lib/webpush/request.rb:175:in `verify_response'

webpush-1.1.0/lib/webpush/request.rb:34:in `perform'

webpush-1.1.0/lib/webpush.rb:44:in `payload_send'

/var/www/discourse/app/services/push_notification_pusher.rb:79:in `send_notification'

/var/www/discourse/app/services/push_notification_pusher.rb:25:in `block in push'

activerecord-6.0.3.3/lib/active_record/relation/delegation.rb:87:in `each'

activerecord-6.0.3.3/lib/active_record/relation/delegation.rb:87:in `each'

/var/www/discourse/app/services/push_notification_pusher.rb:23:in `push'

/var/www/discourse/app/jobs/regular/send_push_notification.rb:7:in `execute'

/var/www/discourse/app/jobs/base.rb:232:in `block (2 levels) in perform'

rails_multisite-2.5.0/lib/rails_multisite/connection_management.rb:76:in `with_connection'

/var/www/discourse/app/jobs/base.rb:221:in `block in perform'

/var/www/discourse/app/jobs/base.rb:217:in `each'

/var/www/discourse/app/jobs/base.rb:217:in `perform'

sidekiq-6.1.2/lib/sidekiq/processor.rb:196:in `execute_job'

sidekiq-6.1.2/lib/sidekiq/processor.rb:164:in `block (2 levels) in process'

sidekiq-6.1.2/lib/sidekiq/middleware/chain.rb:138:in `block in invoke'

/var/www/discourse/lib/sidekiq/pausable.rb:138:in `call'

sidekiq-6.1.2/lib/sidekiq/middleware/chain.rb:140:in `block in invoke'

sidekiq-6.1.2/lib/sidekiq/middleware/chain.rb:143:in `invoke'

sidekiq-6.1.2/lib/sidekiq/processor.rb:163:in `block in process'

sidekiq-6.1.2/lib/sidekiq/processor.rb:136:in `block (6 levels) in dispatch'

sidekiq-6.1.2/lib/sidekiq/job_retry.rb:111:in `local'

sidekiq-6.1.2/lib/sidekiq/processor.rb:135:in `block (5 levels) in dispatch'

sidekiq-6.1.2/lib/sidekiq.rb:38:in `block in <module:Sidekiq>'

sidekiq-6.1.2/lib/sidekiq/processor.rb:131:in `block (4 levels) in dispatch'

sidekiq-6.1.2/lib/sidekiq/processor.rb:257:in `stats'

sidekiq-6.1.2/lib/sidekiq/processor.rb:126:in `block (3 levels) in dispatch'

sidekiq-6.1.2/lib/sidekiq/job_logger.rb:13:in `call'

sidekiq-6.1.2/lib/sidekiq/processor.rb:125:in `block (2 levels) in dispatch'

sidekiq-6.1.2/lib/sidekiq/job_retry.rb:78:in `global'

sidekiq-6.1.2/lib/sidekiq/processor.rb:124:in `block in dispatch'

sidekiq-6.1.2/lib/sidekiq/logger.rb:10:in `with'

sidekiq-6.1.2/lib/sidekiq/job_logger.rb:33:in `prepare'

sidekiq-6.1.2/lib/sidekiq/processor.rb:123:in `dispatch'

sidekiq-6.1.2/lib/sidekiq/processor.rb:162:in `process'

sidekiq-6.1.2/lib/sidekiq/processor.rb:78:in `process_one'

sidekiq-6.1.2/lib/sidekiq/processor.rb:68:in `run'

sidekiq-6.1.2/lib/sidekiq/util.rb:15:in `watchdog'

sidekiq-6.1.2/lib/sidekiq/util.rb:24:in `block in safe_thread'

We are seeing thousands of these. Is this… normal?