I can't debug a routine assigned to a Button's OnAction.

[FableoMyUsername]

Good morning
I can't debug a routine assigned to a Button's OnAction. Debugging just doesn't fit. I have attached the code to understand better. Anyone know how to debug?
Thank you
Fabrizio

Public Sub Rettangoloconangoliarrotondati3_Click()
    Dim btn As Button, t As Range, sht As Worksheet, i As Long
    Dim lRiga As Long

    Set sht = Sheets("FORMARTICOLI")

    'sht.Buttons.Delete
    
    lRiga = sht.Range("A" & sht.Rows.Count).End(xlUp).Row

    For i = 2 To lRiga 'sht.Cells(Rows.Count, "A").End(xlUp).Row 'Numero righe
        Set t = sht.Cells(i, 6) 'Colonna dove viene creato il bottone
        Set btn = sht.Buttons.Add(t.Left, t.Top, t.Width, t.Height)
        With btn
          .OnAction = "CreateButton"  'Azione del bottone creato
          .Caption = "Segna Articolo : " & sht.Cells(i, 2).Value
          .Name = "btn" & sht.Cells(i, 2).Value & "_" & i
        End With
    Next i
End Sub


Public Sub CreateButton()

    Dim RowNumber As Long, sht As Worksheet
    Dim c As Range

    Set sht = ActiveSheet
    
    MsgBox Application.Caller

    RowNumber = CLng(Split(Application.Caller, "_")(1))

    Set c = sht.Cells(RowNumber, "F")

    If c.Value = vbNullString Then
        c.Value = "User: " & Application.UserName & vbNewLine & "Date: " & Date

        If Date <= ActiveSheet.Cells(RowNumber, "E").Value Then
            c.font.color = RGB(1, 125, 33)
            c.Interior.color = RGB(0, 255, 127)
        Else
            c.font.color = vbRed
            c.Interior.color = RGB(255, 204, 204)
        End If
    Else
        c.Value = vbNullString
        c.Interior.ColorIndex = 2
        c.font.color = vbBlack
    End If

End Sub