Cannot sign in with Anonymous Authentication for a Web API datasource

Hi,

I have been able to successfully connect and pull data through a Web API with anonymous authentication in Power BI desktop. However, after publishing it I cannot configure a scheduled refresh because the data source credentials gives me the following error message("Your data source can't be refreshed because the credentials are invalid. Please update your credentials and try again"). When I try to sign in it only gives a message - "Failed to update data source credentials". I have read some posts here and they mentioned that power bi service can authenticate to only one url - the root url. I updated my code accordingly but I still get the same error.

DataSource Credentials Error

Here is my code.

let
authToken = "Bearer abcdefg...",
Source = Json.Document(Web.Contents("https://emapi.site.com",[ Headers=[#"Authorization"=authToken],RelativePath="/v1/messages"]))
in
Source

Has anyone come across the same issue and resolved it? Thanks in advance.