The Proxy user is the ServiceNow now user who carries out the synchronization between the Exalate node and the ServiceNow instance.
The minimum permissions required for the Proxy user are:
The best approach is to create a new role and add the above permissions to that role.
Make sure that along with these basic roles, the Proxy user is also a member of ITIL or similar.
To allow you to add comments to incidents (or whatever entity you want to sync), add 3 ACLs (create, read, write) on sys_journal_field to the Exalate role.
And as the last step, make the Proxy user a member of the Exalate role.
Note that the Proxy user can be used to log in to the Exalate console.