Explanation/Reference:
Configure app requests and SharePoint Store settings
To configure SharePoint Store settings
1. Verify that the user account that is performing this procedure is a member of the Farm Adminis- trators group.
2. In Central Administration, on the Apps page, in the SharePoint and Office Store section, click Configure Store Settings.
3. On the SharePoint Store Settings page, verify that the selected web application is the web appli- cation that you want to configure.
If you want to switch to a different web application, click the down arrow next to the web application URL to change to a different web application.
4. To allow or prevent apps for Office from the Office Store to be started when a user opens a docu- ment in the browser, select an option for Should apps for Office from the store be able to start when documents are opened in the browser?
1. Select Yes to allow apps for Office from the Office Store to start.
2. Select No to prevent apps for Office from the Office Store from starting.
Reference: Manage the App Catalog in SharePoint 2013