Which priest of Bethel told Amos to go prophesy in Judah instead?

Answer: Amaziah

Amaziah the priest of Bethel accused Amos of conspiracy and told him to flee to Judah and never prophesy at Bethel again.

“Then Amaziah the priest of Bethel sent word to Jeroboam king of Israel, saying, “Amos has conspired against you in the midst of the house of Israel. The land cannot bear all his words,”— Amos 7:10 (BSB)