Reload dataflow from powershell script

Hi all,

I've previously used powershell to reload a dataset. This is the script I've slightly modified:

https://insightsquest.com/2019/03/03/refresh-power-bi-datasets-with-powershell/

https://docs.microsoft.com/en-us/powershell/power-bi/overview?view=powerbi-ps

I've used the same powershell module to get all the necessary ID's to create my refresh link for a dataflow according to this article:

https://docs.microsoft.com/en-us/rest/api/power-bi/dataflows/refreshdataflow

Yet when I try to reach the link with a POST request I get this error. The same command with a link to refresh a dataset does work.

Error

Any suggestions?