No Authorisation REST API after Publish Header

Hi all,

I have designed a dashboard within Power BI Desktop using our own data. This data is accessed using a REST API which is authorized using a token in the header. Everything works fine, but then I publish to Power BI Services and want to schedule the refresh. It shows a 400 error. It seems to be that the header is lost during publish?

I checked for hours on forums, but couldn't find any real solution. The only thing I found was this topic (https://community.powerbi.com/t5/Service/web-contents-with-specified-headers-works-in-PBI-desktop-but/td-p/22786/page/2) but without any solution. Can someone help me to fix this final piece?

Thanks in advance.