Site Owners can add built-in apps to a SharePoint site.
NOTE: The SharePoint app store is disabled. All third-party apps must go through a formal review and risk assessment. Please contact the EASI SharePoint Support Team if interested.
If site owners encounter an error denying access to add an app to their site, they can switch to classic SharePoint to create the apps.
You'll be directed back to the Site contents where the new app is listed.
To return to the modern SharePoint look, select Exit classic experience (bottom left corner) or close the tab.