El-Kaabi further cemented his reputation in the competition by scoring a stunning volley to open the scoring, while Dessers equalized with a cool finish after receiving a precise pass from Vaclav Cerny.
The two sides remain level on points in the Europa League with seven each from four games.
The pre-match chatter was dominated by the omission of Rangers captain James Tavernier from the starting XI. He was replaced by Dujon Sterling as Philippe Clement - whose position has been the subject of intense scrutiny following a poor start to the Scottish Premiership season - made three changes to the side that edged Motherwell to reach the Scottish League Cup final.
Both sides made energetic starts to the first half, trading attacks early on. The best of the opportunities fell to Dessers, who failed to convert.
TrendingKonstantinos Tzolakis came out on top of the Rangers striker on two occasions before the break, keeping him out one-on-one before denying him from close range after an impressive run and ball into the box from Cerny.
Dessers eventually got his goal after the hour mark - his second in two games after scoring in the semi-final victory at the weekend.
Rangers boss Phillipe Clement:
"The only minor - but it stays an important - thing is a disappointment that we didn't win the game. That's the next step we need to take - to win these kind of games by being more efficient. But I saw a lot of positive things and I need to praise the whole team for that."
On James Tavernier's omission:
"It's never an easy decision. I want more than one captain in the group. If you come at a certain age you cannot play 60 games anymore at the same level. We talked about that before the season.
"He [Tavernier] will play more games this season and it's about competition for the spots for everybody.
"It's not about one player or one ego, it's about one team winning together. And he showed it also by playing in a higher position, that's what I expect, that is Rangers. One team, one family, everybody going for one goal."