Leverkusen dominated possession of the ball throughout the Europa League final, they also continued to try to build attacks even though they ultimately failed to score a single goal. Leverkusen's defense was really bad in that match, of course this was what Atalanta took advantage of to find a goal.
Yes, Leverkusen won the ball possession. If we learn their formation and the players chosen as starting lineup, it was clear they planned to dominate the ball possession since the early of the match. But Xabi Alonso forget that with no pure striker in the attacking line, it will be harder to score goals. Moreover, they were playing against Atalanta which has a strong defense. As the result, they scored 0 goal in the match.