How to get Bearer Token for Power BI Rest API?

Hi guys.

I am trying to create a report using Power BI Rest API to get the refresh schedules of datasets so I can setup Alerts which will later be used in Flow to trigger refreshes.

I've used the documentation from here https://docs.microsoft.com/en-us/rest/api/power-bi/ and have managed to compile the data.

In order to pass authentification and test, I've used the Try It button to get the Bearer Token and signed in Annonymously, passing the token through the header, but I am having trouble finding how to get that token automatically. I've been reading through every documentation possible but cannot get my head around how to do it.

Please can you help?