using Excel REST APIs sharepoint online in power bi

Hi All,
      I'm a newbie here but need to get up to speed with PowerBI.
I'm trying to visualise Audit Logs( I have setup some logs that writes to excel online) in sharepoint results using Power BI.
I'm sure this should be possible and i try connecting through ths url below:-

http://xxx.sharepoint.com/_vti_bin/ExcelRest.aspx/Audit/Run_a_custom_report_2016-08-20T212904.xslx/Model/Tables('Tablel')?$format=json

But can't get it to work and not sure if this is for only Sharepoint on premise and not online after going through this URL

https://msdn.microsoft.com/en-us/library/office/ff394530.aspx

Also i did setup a content activity report in my sharepoint online

-Content viewing  doesn't work and returns error sorry something went wrong

-Content vmodification works and outputs an excel online which i'm tying to use

Thanks in Advance nd hope someone can direct me in a good direction