When creating new users in ServiceNow UI, the users should have certain permissions to access metadata and, implicitly, have access to the SAP Open Connectors common resource feature. To have access to this feature, the user should be a sys_user with permission rights to access the sys_dictionary table. The sys_user permission is usually by default part of the following roles: admin, delegated_developer, user_admin, catalog, and cloud_admin. 

 To see the definitions of the roles directly in the Service Now account, you can navigate to the Security tab and access the Roles: 

Also, ServiceNow offers the possibility of defining a new role and apply ACL rules (Access Control Rules) which means one can create a custom role with custom permissions.