Step 1

Go to https://outlook.office365.com/owa/?path=/options/manageapps
https://outlook.office.com/?path=/options/manageapps
(you'll have to sign in with your Office 365 account)

Step 2

Click My add-ins

Scroll to Custom add-ins and choose Add From URL...

Step 3

Enter URL

https://freebusy.io/outlook/officestore.xml

Click Ok, accept the warning and then click Install

Step 4 - Outlook desktop

When you compose or reply to an email in Outlook desktop and when you schedule or reschedule a meeting in Outlook desktop, you'll be able to open the FreeBusy add-in from the ribbon:

Step 4 - Outlook web

When you compose or reply to an email in Outlook web you'll be able to open the FreeBusy add-in from the lower toolbar (might be necessary to search it in the drop-down menu):

When you schedule or reschedule a meeting in Outlook web, you'll be able to open the FreeBusy add-in from the upper toolbar in the event editing extended dialog:

Did this answer your question?