You need site administrator permissions to perform this step.
1. Open a site as site administrator.
Add the add-in to the site
2. Click the cog icon to open the menu and choose 'Add an app' and choose 'SharePoint Connector for Confluence' under 'Apps you can add' (see below image):
Images 1 and 2: Add the SharePoint Connector for Confluence app to a site (click to enlarge)
3. Trust the add-in:
Image 3: Trust the SharePoint Connector for Confluence app (click to enlarge)
The add-in will be installed:
Image 4: App installation notice (click to enlarge)
Check that you can add add-in parts (web parts)
Click Add a page to add a page:
Add the app part:
The add-in part should now be visible. Check that it behaves as expected and documented.