Need to add the sum of the Leave count to another sharepoint list using ID and proper Name

Hi,

I am working on the three SharePoint lists

--------------------------------------------------

1- Leave Applied by users ( LeaveID - Lookup from Balance Leave, Total Leave, LeaveType, RequestedBy, RequestedTo)

2 - User leave details (UserID, Name, LeaveID - Lookup from balance Leave, LeaveType, TotalLeaveApply, BalLeave)

3 - Balance Leave (LeaveID, LeaveType, Days)

-----------------------------------------------------

For the 'Leave Applied by users' list data updating from the power apps ( I already created).

I need to do one task that is,  need to get the sum of TotalLeave in this list('Leave Applied by users') using name with their leavetype and LeaveID and I need to add this count on the 'User Leave Details' list with leaveID and Proper name.

How can do this task please anyone give suggestion for me! 

Thanks