Consume SPO REST API in PowerShell with ACS App Only Credentials

I was working with customer who wanted to quickly test his App permissions. He first created the App Credentials (Client ID & Client Secret) via https://tenant.sharepoint.com/sites/yoursite/_layouts/15/appregnew.aspx page. Then it gave it some permissions via the https://tenant.sharepoint.com/sites/yoursite/_layouts/15/appinv.aspx page. After having created his App, my customer did save its client ID and client secret but didn’t save its…

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