Hello M.Cain,

Add this macro to the worksheet whose formula is to be copied to the next record. Change the column letter, shown in blue in the code, to match the one you will be using.
Private Sub Worksheet_SelectionChange(ByVal Target As Range)

  Dim C As Variant
  Dim R As Long
  
  Application.EnableEvents = False
  
    With ActiveSheet
      C = "D"
      R = Target.Row
      LastRow = .Cells(.Rows.Count, C).End(xlUp).Row
    End With
    
    If Target.Row = LastRow + 1 Then
       ActiveSheet.Cells(R, "D").FillDown
    End If
  
  Application.EnableEvents = True
  
End Sub
How to Save a Worksheet Event Macro
1. Copy the macro using CTRL+C keys.
2. Open your Workbook and Right Click on the Worksheet's Name Tab for the Worksheet the macro will run on.
3. Left Click on View Code in the pop up menu.
4. Paste the macro code using CTRL+V
5. Change the column letter now.
6. Save the macro in your Workbook using CTRL+S

Sincerely,
Leith Ross