Fetch User Information on PBI from SharePoint site collection

Dear Experts,

I have created one Canvas based "Help Desk" application over the Power Apps and need to create a report over the PBI.

The problem is;

- Unable to locate the details of AuthorID/AssignedToId on HelpDesk. 

Can anyone help, from where I get the information of userinformation other than https://xxxxxxxxx.sharepoint.com/_vti_bin/listdata.svc

because, the reference is not correct.

For example: My id over the HelpDesk is "19" but on sharePoint List data is "33". 

The help desk location is :

https://xxxxxxxxxxx.sharepoint.com/sites/helpDesk

Regards,

Ahmed