To manage apps on your SharePoint Online tenant, you must create an App Catalog. This will allow you to manage weather or not users are allowed to “purchase” and add Apps from the SharePoint Store.
To configure your catalog you must first create one. To do so, browse to your SharePoint Admin Center, go to App and click on the App Catalog link
From there, simply create a new App Catalog by clicking ok.
Give you catalog a Title, proper URL, Language, Time Zone, Administrator and Storage Quota
Once this job runs, you will have an App Catalog. The SharePoint site will look like this
You’re now able to specify if users are allowed to purchase Apps from the SharePoint Store or not. To do so, go back to the SharePoint admin center and click Configure Store Settings.
In the store settings, specify the behavior that works best for your organisation. In my case, I select no then click ok.
Now if a user tries to purchase an App, he will have to go trough a request process
The App will show in the requested Apps section until an administrator allows or denies the request.
It will also show in the App Request list in the App Catalog we created earlier for the administrator.
Once the App is purchased by the administrator, it becomes available in the Apps you can add section of the Add an app page for end users to use it.
That’s pretty much it. Once you’ve setup the App Catalog, you can start manager your Apps better and most importantly, manage Apps requests.
I hope this helps,