Error while Provisioning Reporting Services Subscriptions in sharepoint

When trying to create subscriptions for SQL Server Reporting Services when hosted in SharePoint Integration mode , you might get an error which says

“The EXECUTE permission was denied on the object 'xp_sqlagent_notify', database 'mssqlsystemresource', schema 'sys'.”

To Fix this issue,

1. Login to Sharepoint central administration and navigate to the “Manage Reporting Services Application” page
   
   
2. Click “Provision Subscriptions and Alerts” 
3. Click “Download Script” and this will download a file named “SSRS-GrantRights.sql”
4. Execute the script on your SharePoint database server