Invalid Connection Credentials When Adding API to On‑premises Data Gateway

there is no need to add the historycontact endpoint. Implement a custom action in your connector that adds it as a relative parameter.

Thankyou, lbendlin, for your response.

Hi ihavequestionto,

We appreciate your inquiry submitted through the Microsoft Fabric Community Forum.

As per my understanding, the issue arises because Power BI Service and Gateway require a valid and reachable Base URL during data refresh. In your case, accessing only api.mktzap.com.br/ returns a "404 Not Found" error, which leads to the gateway authentication failure. While Power BI Desktop may sometimes handle this scenario more leniently, the Service necessitates a successful connection even to the base URL.

Kindly follow the steps below, which may help to resolve the issue:

1. Update your API connection so that the Base URL points to a valid path—for example, api.mktzap.com.br/company/ instead of the root URL alone.
2. Use the RelativePath and Query options to append the specific endpoint (such as /historycontact) and any query parameters like x-page.
3. Ensure that in Power BI Service, the Authentication Method is set to Anonymous (particularly if you are using Bearer tokens in the headers) and the Privacy Level is set to None.

If you find our response helpful, kindly mark it as the accepted solution and provide kudos. Your support will be beneficial to other community members encountering similar queries.

Thank you.

Hi ihavequestionto,

We have not received a response from you regarding the query and were following up to check if you have found a resolution. If you have identified a solution, we kindly request you to share it with the community, as it may be helpful to others facing a similar issue.

If you find the response helpful, please mark it as the accepted solution and provide kudos, as this will help other members with similar queries.

Thank you.

Hi ihavequestionto,

We wanted to check in regarding your query, as we have not heard back from you. If you have resolved the issue, sharing the solution with the community would be greatly appreciated and could help others encountering similar challenges.

If you found our response useful, kindly mark it as the accepted solution and provide kudos to guide other members.

Thank you.

Hi ihavequestionto,

We are following up to see if your query has been resolved. Should you have identified a solution, we kindly request you to share it with the community to assist others facing similar issues.

If our response was helpful, please mark it as the accepted solution and provide kudos, as this helps the broader community.

Thank you.

Hi ihavequestionto,

Thank you for the update and sharing your insights and approach in resolving the issue.

We kindly request you to mark your response as the accepted solution, as this will help other community members find answers to similar challenges more efficiently.Please continue leveraging the Fabric Community for any further assistance with your queries.

Thank you.