I have created macro VBA in pptm , my doubt is how to call macro function whenever ppt open, if anybody know please guide me.

Sub Auto_Open()
  
Dim MyPath As String
    Dim MyFile As String
    Dim LatestFile As String
    Dim LatestDate As Date
    Dim LMD As Date
    
    MyPath = "C:\Workspace\OneModernize\April\Mywork\excelAccesssNet\"
    If Right(MyPath, 1) <> "\" Then MyPath = MyPath & "\"
    MyFile = Dir(MyPath & "*.pptm", vbNormal)
    If Len(MyFile) = 0 Then
        MsgBox "No files were found...", vbExclamation
        Exit Sub
    End If
    
    
    Do While Len(MyFile) > 0
        LMD = FileDateTime(MyPath & MyFile)
        If LMD > LatestDate Then
            LatestFile = MyFile
            LatestDate = LMD
        End If
        MyFile = Dir
    Loop
   ' Workbooks.Open MyPath & LatestFile
  If (LatestFile = "Test1234.pptm") Then
  
LMD = CDate(Left(LatestDate, 9))
Dim Expiry As Date
'Expiry = DateValue(Range("A1")) + 7
Expiry = LMD + 7



If LMD > Expiry Then
MsgBox "This File Has Expired. Please Download the latest version!", vbCritical, "File wile close"
Application.DisplayAlerts = False
ActiveWorkbook.Close
Application.DisplayAlerts = True
Application.Quit
Else
MsgBox "You Have " & Expiry - Date & " Day(s) Left", vbInformation, "file  Expires on " & Expiry
End If
End If

End Sub