～たがっています is "want to (verb)" for the third person.
Kare wa nihon ni ikitagatte imasu. --> He wants to go to Japan.
Kare wa nihon ni ittagatte imasu. --> It doesn't exist.
Kare wa nihon ni ikitagatte imashita. --> He wanted to go to Japan.
Generally we use ～たいです(want to verb) for the first and second person and ～たがっています for the third person but there are cases in which we say ～たいです for the third person.
I hope this was helpful and the professional teachers or other people explain more about it.