By default, all logged-in users can use Merge Agent for Jira. You can restrict permissions either globally or per project. A user has access by either having global permissions or project permissions, they don’t need both permissions.
Navigate to the “Global Permissions” within the Jira System settings. At the bottom, you will find the Merge Agent for Jira permission. A user with this permission will be able to access Merge Agent for Jira for all issues in all projects, no matter how project permissions are configured.
Navigate to the Permission scheme of a project. At the bottom, you will again find the Merge Agent for Jira permission. A user with this permission will be able to access Merge Agent for Jira for all issues within the projects using this permission scheme, no matter how global permissions are configured.