FCM configuration - Grant permission for another Project

Configuration for forwarding Cloud Messages from Verestro FCM to Client's FCM.

Visit console.cloud.google.com/iam-admin

Select Grant Access 



In Assign roles section select a role from a list



Select option Manage roles



Select Create role



Fill title (1) and ID (2) fields, and click on Add permissions (3)



In Add permissions window, using filter field find cloudmessaging.messages.create value



Mark found permission, and add it



After adding permission, create the role



There should appear our new created role



Visit https://console.cloud.google.com/iam-admin/iam

Select Grant access option again



Input e-mail in New principals field (1) for account which will be using the new role (principal provided directly or in configuration file), and next in Assign roles section select a role (2) from a list



Using filter field, find new created role



After choosing a role, save the principal access



There should appear new principal with new role on the list