As an Office365 admin, you can deploy Office add-ins for the users in your organization. You can do this by using the Centralized Deployment feature in the Office365 admin center.
Personal Installation
If you have an active Microsoft account, you can install the AHAU 260 add-in directly from the store.
For that, go to the Microsoft Office Store page with the add-in and click the “Get it now” button.
Check the box so you agree with Microsoft’s Terms and Conditions.
After these steps, you will be redirected to a new page, where the add-in will be added to your Outlook account.
Organizational Installation
We recommend that you manage the add-in for your Exchange Online organization via Centralized Deployment in the Office 365 admin center. For more information, see Manage deployment of Office 365 add-ins in the Office365 admin center.
Before you begin, see Determine if Centralized Deployment of add-ins works for your Office 365 organization.
Download the manifest file here.
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” 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.
Download the manifest file here.