en_tn/2co/02/12.md

Though a door was opened to me

Just like an open door allows one to walk through, so Paul was given an opportunity to share the gospel message at Troas. AT: "I was given an opportunity" - (See: rc://en/ta/man/translate/figs-metaphor)

my brother Titus

Paul often refers to other people who share in his ministry his brother in Christ.

So I left them

"So I left the people of Troas"