HowTo use Azure cmdlets in Azure Schedule

A Runbook schedule can be triggered every hour. If you need a smaller interval, like every minute, you can use the Azure Scheduler to do so. So I went to the Azure Portal, created an Azure Schedule instance (with a job collection tier of at least basic, to be able to create schedules that are triggered every minute) and called a Runbook via webhook. The Runbook contains a cmdlet that results in an error 🙁