Object vs adverbial

In the sentence:

"The teachers in our school are nice."

Is "in our school" an adverbial or part of the subject "The teachers in our school"?

Wondering because it would apply then to stuff like

"The man from Spain is funny."

With "from Spain" as an adverbial.

Furthermore:

"We fed the boys chicken."

Is "the boys" the IO and "chicken DO?

Thanks :))