Can’t add Southwest itinerary to calendar

I can’t seem to add my flight information for an upcoming trip. It was booked on Southwest. It used to be that the information would just pop up at the top of the email and it would give you an option to add it to the calendar but now it doesn’t. Does anyone know how to do this? I’m sure it’s painfully obvious and I am missing something.I have another friend whose iPhone just did automatically so maybe I’m missing some kind of setting that I don’t have turned on?