From which port did Jonah board a ship to flee from the LORD?

Answer: Joppa

Jonah went down to Joppa, found a ship bound for Tarshish, paid the fare and went aboard to flee from the LORD.

“Jonah, however, got up to flee to Tarshish, away from the presence of the LORD. He went down to Joppa and found a ship bound for Tarshish. So he paid the fare and went aboard to sail for Tarshish, away from the presence of the LORD.”— Jonah 1:3 (BSB)