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Sign in to Office365 for business with your work account.
Select the app launcher icon in the upper-left, and choose “Admin”.
TIP: “Admin” appears only to Office365 admins.In the navigation menu, choose Settings > Services & Add-ins.
If you see a message on the top of the page announcing the new Office365 admin center, click the message to go to the Admin Center Preview (see About the Office365 admin center).
Choose “Deploy Add-in” at the top of the page.
Choose from one of the following options on the “Centralized Deployment”pageDeployment” page:
I have the manifest file (.xml) on this device: For this option, select Browse to locate the manifest file (.xml) that you want to use.
I have a URL for the manifest file: For this option, type the URL in the field provided.
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