Macro overwrites first row instead of pasting the data on the next row.

I'm trying to get this macro to paste data into the next row but all it does is overwrite the the first row. Can anyone help me please?

Sub ValidateExportData()
'
' ValidateExportData Macro
'
' Keyboard Shortcut: n/a
'
Application.ScreenUpdating = False
Application.EnableEvents = False

Dim DataSource As Worksheet
Dim DataDestination As Worksheet
Dim LastRow As Long
Dim PasteRow As Long

On Error GoTo CleanUp

' Open the destination workbook
Dim TaskCalendar As Workbook
Set TaskCalendar = Workbooks.Open("S:\Task Management Calendar System\Task Calendar.xlsx")

' Set worksheets
Set DataSource = Workbooks("Analysis Request Form.xlsm").Worksheets("Analysis Request Form")
Set DataDestination = TaskCalendarWB.Worksheets("2025")

' Find the last row and move to the next row
LastRow = DataDestination.Range("D" & Rows.Count).End(xlUp).Row + 1

' Copy and paste values from the source to the destination
DataDestination.Cells(PasteRow, 4).Value = DataSource.Range("E11").Value ' Paste in column D
DataDestination.Cells(PasteRow, 5).Value = DataSource.Range("E12").Value ' Paste in column E

' Optional: Save and close the destination workbook
TaskCalendarWB.Close SaveChanges:=True

CleanUp:
Application.CutCopyMode = False
Application.EnableEvents = True
Application.ScreenUpdating = True

If Err.Number <> 0 Then
MsgBox "An error occurred: " & Err.Description
End If

End Sub