Excel Power Query Date Calc using today

[gheyman]

I need to create a new column in a table where it takes todays date minus the date in another column. My "then" needs to be todays date minus [ApprovalDate].

=if [OrderType] = " Requistion" then [ApprovalDate] else ""

Thanks for your help

 

[gheyman]

Formula that is not working:

= Table.AddColumn(#"Added PR Age", "PR Aged", each if [OrderType] = "Requisition" and [ApprovalDate] <> null then Duration.Days(DateTime.FixedLocalNow - DateTime.From([ApprovalDate])) else "")