Hi Qiuyun,
Yes I have checked all of these requirements and they have been met. The Report Server has been registered for Power BI. The issue is when I run a report on the report manager and try to pin a visual to Power BI. I am able to login via the pop-up screen after clicking "Pin to Power BI" but then it just sits there and I get the error message. I think it may have something to do with the firewall settings on the Report Server. Are there certain inbound ports that need to be opened on the Report Server?