Power BI API export returns 403 for semantic models while dataflow backup succeeds

Hi. 403 is usually refering to the api permission scope delegation. I know you said you have reviewed this, but there is a small thing I have seen before that can make a mistake.

You need both report and dataset permission:

And I say again Dataset, because you will see semantic model settings and that's not the same api. Report.ReadWrite.All or both Report.Read.All and Dataset.Read.All

Validate using get reports in group and get datasets in group. If both requests work, then the scope is ok.

In addition, remember that for .pbix reports, exporting a report is subject to the same limitation as downloading a report .pbix file.

As an alternative, you can download as project TMDL using simplepbi library. It uses semantic model and report permission delegation api instead of that one.

https://blog.ladataweb.com.ar/descargar-reporte-o-modelo-semantico-via-api-como-proyecto-tmdl/

I hope that helps