Unable to run Rest API call within Power BI.

Overview

I am unable to run a Rest API call within Power BI. However I can run the same Rest API call within an internet browser successfully.

Detail

Internet Browser Rest API call works fine

1) Signed into application myapplication.com via Microsoft Authentication using [email protected].

2) Entered the following into my browser ... myapplication.com/api/<my Rest API> call.

3) The expected Rest API response was then received within my browser.

The same Rest API call does not work within Power BI

1) Launched Power BI.

2) Signed into Power BI via Microsoft Authentication using [email protected]

3) Selected New data source of type "Web"

4) Pasted the Rest API call into the URL column.

5) Chose 'Organizational account' as the Access Web Content method.

6) For the column "Select which level to apply these settings to" I entered "https://myapplication.com"

7) I clicked the "Sign in" button and I received the following error message ... "The WWW-Authenticate header doesn't contain a valid authorization URL Header value: 'BASIC realm="myapplication.com".

N.B. It is not an option for me to change the Rest API service in the application. I am confused as to why the Rest API call works within the internet browser but not within Power BI.
There is no proxy set within the internet browser I have used in this scenario.