Here, "dressed" is an adjective. He is sick. He got sick. [get - to change state] He is dressed. He got dressed.

"to get dressed" is a phrasal verb, meaning "to put clothes on"

It’s an adjective. Check out the first example in Cambridge dictionary: https://www.google.com/amp/s/dictionary.cambridge.org/amp/english/dressed

It means, put your clothes on.

Hi there, here the verb+ed form is an adjective.