Grant additional permissions to users or groups in a target location.
Prerequisites
You have site collection admin permissions on your targeted site collection(s).
Note: Site collection admin permissions are required even if you have higher admin privileges like SharePoint admin or global admin permissions. For more information, see Microsoft administrative permissions.
Tip: To manage all your site collections, you can connect to your central admin or admin center with SharePoint admin, farm admin, or global admin permissions.
How-to
Select the item you would like to perform the action on from the Explore screen.
Click + Add from the Permissions section in the Quick actions menu.
Verify the target(s) of the action.
Select the user or group you want to include in the report (see below for details).
Select the permission you would like to assign from the Assign permissions dropdown (see below for details)
Select the permission type (if applicable).
Click Apply.
In the case that there are warnings or errors, they will be displayed with details in separate tabs near Results. See the Edit page for how to modify or transform results.
Assign permissions to the selected users or groups by adding them to existing groups, or by giving them explicit permissions.
Add to existing group - Lists all the groups within the target location that you can add the user(s)/group(s) to.
Assign as site collection administrator - Grants site collection administrator permissions to the user(s), or to all users in the selected group(s). Sits collection administrator permissions give users full control over all sites in the target site collection(s).
Add explicit permissions - Assigns specific permissions (such as design, edit, contribute, and read) to the user(s), or all users in the selected group(s). You can select if you would like to apply the permissions to all subsites, lists, and libraries with unique permissions, and to list and library content.
Note: ShareGate Migrate does not support transformations with NT AUTHORITY\Authenticated Users. For more information, see NT AUTHORITY cannot be created.