Automatic Refresh on Premise Power BI report Server

Automatic page refresh is listed here https://docs.microsoft.com/en-us/power-bi/report-server/compare-report-server-service as not being supported on Report Server. And if you are using the version of desktop that is optimized for Report Server you should need even see this as a configuration option. Are you using the version of desktop that aligns with the version of server that you are using? If not you should switch to using that version for any reports you want to upload to Power BI Report Server as you can run into serious issues if you try and upload reports authored in the "cloud" version of Power BI to an on-prem report server

For onpremises Report Server you can try use this Edge addon https://microsoftedge.microsoft.com/addons/detail/power-bi-auto-refresh/icijhcaaliebohihbagbkaefdalkckbd