As we mentioned previously in this chapter, some apps may require rights or permissions to your organization in order to be installed. While site owner permissions are required to add an app to a site, only a user who has been granted the SharePoint Admin or Global Admin role can approve an app if it requires additional permissions.

The permission request flow is a type of approval workflow that's responsible for ensuring the installation request is directed to the appropriate administrators.

When an app requires approval, an automatically-generated email will be sent to an administrator. To approve (or deny) a request, follow these steps:

1. In the approval email, click You can now approve or reject the request here. You will be redirected to the App Catalog approval request for the app. Alternatively, you can navigate directly to the App Catalog, select App requests from the menu, and then open the request.
2. On the Approve or Reject App Request screen, add any comments to the request and click Approve or Reject. 

You can also use the App Requests page to review current and past requests. To do so, follow these steps:

1. Navigate to the App Catalog site and select App Requests from the menu.
2. Select All Requests to see all current and past requests:

3. Now, you can view the request details, as well as revoke approval.

Since the App Catalog is a site collection, you can also delegate authority for app approvals by adding a user as a site collection administrator. Delegating authority for approvals can help lessen the time it takes for users to get access to the applications they need.