OAuth alternative for Power BI Report Server refresh?

Hello,

My organization recently shifted to using MS Project Online. We have an on-prem Power BI Report Server environment and web portal hosting our PBI reports. I recently learned Power BI Report Server does not support OAuth authentication, which eliminates the ability to automatically refresh MS Project Online data.

Has anyone out there identified a work around for this problem? I'm sure this lack of functionality might drive some toward Power BI Pro licensing but it severely hinders those who have to use on-prem solutions for data security reasons. Any information would be greatly appreciated. Thanks.