을 남기고

leave … and

→ 을
phrase Uncommon #12,655
leave … and The object particle 을 follows the thing being left; 남기고 links this action to what follows.
KO: 댓글을 남기고 가세요.
EN: Leave a comment and then go.

좋은 첫인상을 남기고 싶어서요

Because I want to make a good first impression.

— 어바웃 타임 (2013)