VBA IF AND based on two columns

I am totally new in macro's so I would like to know where did I make mistakes in my code.

I just want a simple IF - AND based on 2 different columns and the result should be in the third column

My code is:

   Sub FTL_Customer3()

   Lastrow = Sheets("Raw data").Range("D" & Rows.Count).End(xlUp).Row

   For i = 1 To Lastrow

   If Sheets("Raw data").Cells(i, 5) = "Postponed to next month" And Sheets("Raw 
   data").Cells(i, 13) = "ATP Ship date after EOM" Then
   Cells(i, 7).Value = "OK"
   
   End If
   Next I
   End Sub