John Gill Commentary 1 Kings 22:15

"And when he was come to the king, the king said unto him, Micaiah, shall we go to Ramoth-gilead to battle, or shall we forbear? And he answered him, Go up and prosper; and Jehovah will deliver it into the hand of the king." — 1 Kings 22:15 (ASV)

So he came to the king Being introduced by the officer:

and the king said unto him, Micaiah, shall we go up against Ramothgilead to battle, or shall we forbear? the same question in the same words that was put to the other prophets, (1 Kings 22:6) , only there he uses the singular number, here the plural, including Jehoshaphat with him:

and he answered him, go, and prosper: for the Lord shall deliver [it] into the hand of the king ; the same question in the same words that was put to the other prophets, (1 Kings 22:6) , only there he uses the singular number, here the plural, including Jehoshaphat with him: