modifi code

Sub EnviarMensajes()
    Dim IE As Object
    Dim row As Integer
    
    row = Cells(Rows.Count, 2).End(xlUp).row 'Encontrar ultima fila utilizada
    For i = 7 To row
        Set IE = CreateObject("InternetExplorer.Application")
        IE.navigate "whatsapp://send?phone=+56" & Range("C" & i).Value & "&Text=" & Range("D" & i).Value
        Application.Wait (Now() + TimeValue("00:00:03"))
        SendKeys "~" 'Enter
    Next
    
    Set IE = Nothing 'Clear the object
End Sub