I was looking for a solution to automate the creation of a kiosk mode with a specific website in Microsoft Edge. Because this is easily possible in the UI and there is absolutely no useful documentation about this in pure PowerShell, I reverse-engineered the process. The result is a PowerShell script I put in the answer section
Here is a link to my GitHub repository, where you can find the PowerShell script. As mentioned there, this currently only works in Windows 10 (I will update it in the future) https://github.com/ProRedMax/Kiosk-Mode-with-pre-defined-website-Powershell