BI Server Data Source Windows Authentication Problem with Share Excel File

I have setup Power BI server on 172.17.5.15 (PC1) and Keep an Excel file on another (PC2) whose address is 172.17.5.22. I uploaded the test pbix file to the Power BI server, which worked fine. But when I tried to connect to the data source it's asking for windows authentication. I tried to give PC2 user name and password but it's not working. Please help me with what windows user id I will provide or how I write the user ID. Example: My user ID MIS_Share.