Power BI Get Activity Events API Error

I am trying to get the activity data from the Power BI REST APIs, using the Get Activity Events API call. Following the solution shown in the video: https://bielite.com/blog/building-a-power-bi-admin-report/

However, I keep getting the below error:

Expression.Error: The 'Authorization' header is only supported when connecting anonymously. These headers can be used with all authentication types: Accept, Accept-Charset, Accept-Encoding, Accept-Language, Cache-Control, Content-Type, If-Modified-Since, Prefer, Range, Referer

I am authenticating anonymously using the app which has tenant ready and write application permissions.

Appreciate if you can provide an guidance on how to fix this error. Below are the screenshots of my functions and query.