2yr old and mask mandate

My family are taking a trip in Sept. and will be flying with Southwest and 2 flights to our destination. Currently they require 2 yrs olds to wear mask. Our daughter just turned 2 in may. This will be her first time to have to wear a mask. Looking for some advice or recommendations on how to go that.. not looking forward to a possible tantrum with mask situation. Heard some families had to de plane because of their 2 yr. not wanting to wear mask