Get certified for free when you join Fabric Data Days 2026 and dive into Fabric, Power BI, SQL, AI, and other essential data skills.
Join nowJuly 7 - July 17 | Round 2 of the Power BI Dataviz World Championships. Don't miss your chance! Learn more
I have built a report that pulls some data directly from a REST API. This API requires authentication, and the following code worked for me to access and pull the data directly into PowerBI:
let
Source =
Json.Document(Web.Contents("https://somesite.com/Web/",
[Headers=[
AccountLoginName="user",
AccountPassword="pass",
SourceSystemID="123",
DomainID="1"],
RelativePath="path/to/api/endpoint"However, I loaded the report today to make some modifications, and the following error was presented to me:
Expression.Error: The 'AccountLoginName' 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, Referer
Can anyone give me a nudge in the right direction?
Solved! Go to Solution.
Got it sorted. Realized that the error I was seeing was not from PowerBI but from the API I was trying to connect to. Somehow my datasource stopped trying to login "Anonymous" and had got set to "Basic" A quick reset, and we are good.
This pointed me in the right direction.
https://community.powerbi.com/t5/Service/Anonymous-access/m-p/277217/highlight/true#M33295
Got it sorted. Realized that the error I was seeing was not from PowerBI but from the API I was trying to connect to. Somehow my datasource stopped trying to login "Anonymous" and had got set to "Basic" A quick reset, and we are good.
This pointed me in the right direction.
https://community.powerbi.com/t5/Service/Anonymous-access/m-p/277217/highlight/true#M33295
Join us in Barcelona for FabCon and SQLCon, the Fabric, Power BI, SQL, and AI community event. Save €200 with code FABCMTY200.
If you love stickers, then you will definitely want to check out our community sticker challenge, Barcelona edition!
Check out the July 2026 Power BI update to learn about new features.
| User | Count |
|---|---|
| 30 | |
| 26 | |
| 23 | |
| 23 | |
| 14 |
| User | Count |
|---|---|
| 47 | |
| 33 | |
| 20 | |
| 18 | |
| 16 |