your trailer is riding on the spare. You pull the trailer up onto a couple of boards under the good tire so the flat dangles, and remove it. Then proceed at reduced speed top a place of repair.
If you want one, the spare carrier is an option still available, it goes under the front of the trailer between the a-frame. The stone guards are an option, and it just depends on what options were checked off when the trailer was ordered. They are also still available.
Meddle not in the affairs of dragons, for you are crunchy, and taste good with ketchup.