I came across a need to know when a certificates and secrets are about to expire on Azure app registrations, but there was no native way for me do this, expect to just scroll down the application registration list and look for “Expirer soon”, and that didn’t really do it for me.
So, I decided to look for way to get notified a number of days before a secret or a certificate will expire using PowerShell. I ended up writing this script and then running it using an Automation Account in Azure, but you can run this script everywhere, if you have the Microsoft Graph PowerShell module installed on the platform of your choice.