To be honest, I didn't watch this match because my attention was on Juventus vs Sevilla. but referring to the statistics of the match, this match took place quite evenly. So, I don't think Rome's 1-0 advantage can be said to be safe. especially in the second leg, Leverkusen played as the home team. at least, they have a strong drive and motivation to equalize the aggregate and even win the game with a bigger score. anyway anything can happen, besides Rome did not play very fantastically.
So, Leverkusen still has a chance to overthrow AS Roma. especially if we refer to the available odds, the bookie favors Leverkusen. maybe in the second leg, Leverkusen can score 1 goal. which in the end the fight continued in extra time, it could even go to a penalty shoot-out. well, I'm pretty sure this fight is pretty competitive. in the end, the two coaches will compete tactics and strategies. although most likely, Jose Mourinho will prefer defensive tactics and rely on counterattacks.
For some reason, I don’t see quotes for the return games now, but here is a quote for the results:
UEFA Europa League - Winner
AS Roma 3.15
Juventus Turin 3.40
Sevilla FC 3.70
Bayer Leverkusen 4.60
After Roma got the advantage they became clear favorites and I don't think Bayer has much chance at home - I would rather believe that Roma will win again by scoring on the counterattack. And in general, if you look at how the Italian teams play this season, you can say that one goal of the advantage is enough for them, hehe.
As for Sevilla, even despite the success in the first game, they are still underdogs, although the difference is small.