Prerequisites
You must be:
an admin of the Confluence Cloud site
either a technical contact or billing contact of the Confluence Cloud instance
To verify, log in to MyAtlassian and ensure the Confluence Cloud instance appears on the Licenses page.
Guide
In your Confluence Cloud site
choose the Confluence global Settings cog icon in the top-right corner
go to Apps > Find new apps
When the Find new apps screen loads, search for Page Approval for Confluence
open the marketplace page for the Cloud app
choose Get app
in the dialog box choose Get it now
Once Atlassian confirm in an an on-screen notification that the app has been installed - you're all set!
choose Get Started to use open the onboarding guide for the app or select Manage App to check the app license
If the app requires a paid license, you will be provided with a minimum of a 30-day free trial.