To install the SharePoint Online Connector for Confluence, go through the pages in order, if not otherwise indicated on the page.
Prerequisites for Administration
All communication between Confluence and SharePoint Online is done by the client of the end user (i.e. browser). A direct connection between the two servers is not necessary. In order to use this app the user therefore needs to have access to both systems with the browser running on the local machine. The same principle applies to the administration and the initial setup.
Precondition: Configure authentication for SharePoint Online AP
Azure Administrator who is Global Administrator for the Azure Active Directory tenant