Step 1: Add an Application Catalog in O365

The first step involves creating an application catalog and uploading and registering the app. 

NOTES:

• Creating a new app catalog is not mandatory if you have an existing app catalog you'd like to use.
• New O365 tenants do not have an app catalog so you'll need to create one.

1. Login to your O365 tenant using the account using your Global Admin permissions. 
2. Go to the Admin section.
   
3. Choose Admin centers > SharePoint. 
   
4. Go to More features > Apps > Open. 
   
5. On the Apps page, click App Catalog.
   
6. Select Create a new app catalog site and click OK.  
   
7. On the Create App Catalog Site Collection page, configure the following information and click OK.
   • Title. Enter a Title for the application
   • Web Site Address. Enter the address of the website.
   • Administrator. Select one Administrator. 
     

An app catalog site collection has been created.

8. Go to SharePoint admin center Sites > Active sites > Open the App Catalog site and click the App Catalog URL. 
   
9. On the site collection properties window, click the Site Collections link. 
   

Continue to Step 2.