How to paste the specific text in an entire column based on heading in VBA macro

[Jarvis 0617]

Hello, in my excel workbook (Bulk_Upload.xlsm, Worksheets("Sheet1"), I have two columns (1st column header = Task type, 2nd column header = Active) when I run the macro, I want to automatically fill the some fixed Text in Task Type = SFLA & Active = TPR) in these two columns, and it has to fill the data until the beside column's last row range.
I'm new to macro, and I'd appreciate it if someone could assist me.

 

[BSALV]

Sub test()
     With Sheets("sheet1")
          myrow = .Range("AD" & Rows.Count).End(xlUp).Row       'last row of Ad
          With .Range("AE2").Resize(myrow - 1, 2)               'this range of AE:AF
               .SpecialCells(xlBlanks).FormulaR1C1 = "=R[-1]C"  'put a formula in the blank cells
               .Value = .Value                                  'replace formulas with values
          End With
     End With
End Sub