The most striking characteristic that Camus's The Fall / La Chute and Daoud's Meursault, contre-enquête have in common is that they are written as a second-person narrative.
In La Chute, the main character tells his story to another person whom he addresses as "vous" ("you", polite form); neither the main character nor the other person formally introduce themselves to each other. The same applies to Meursault, contre-enquête, although here the main character addresses the other person as "tu" ("you", informal form). We gradually learn that he is the brother of the "Arab" shot by Meursault but we find out his name only indirectly, when he cites the words of his dead brother's ghost.
In both novels, the narrator and the listener initially meet each other in a bar; the bar Mexico-City in Amsterdam in La Chute and the bar Djebel Zendel (named after a mountain) in Oran in Meursault, contre-enquête. The chapters that follow continue the narrative on subsequent encounters.
We learn very little about the "listener" in both novels. In La Chute, the listener is a compatriot, i.e. a Frenchman. We learn at the very end of the novel that is a lawyer, just like the narrator used to be. In Daoud's novel, we gradually learn that the listener comes from Paris, that he has read the novel about Meursault and that he wants to write some sort of thesis based on it.
We don't find out what this secondary character says or does, except when the main character responds to or comments on something said by the listener. the closest analogy to this type of narrative is overhearing one side of a telephone conversation, so you can only infer what the person at the other line has said based on the reactions of the person you can actually hear.
Below is an example from the first chapter of Daoud's novel:
En poussant la porte de ce bar, tu as ouvert une tombe, mon jeun ami. Est-ce que tu as le livre dans ton cartable? D'accord, fais le disciple et lis-moi les premiers passages ...
Tu as compris? Non? Je t'explique.
When you pushed the door to this bar, you opened a grave, my young friend. Do you have the book with you in your briefcase? OK, play the disciple and read to me the fist passages ...
Have you understood? No? I'll explain it to you.
Below is an example from the first chapter of La Chute:
Quand je vivais en France, je ne pouvais rencontrer un homme d'esprit sans qu'aussitôt j'en fisse ma société. Ah! je vois que vous bronchez sur cette imparfait du subjonctif.
When I lived in France, I could not meet a wit without seeking his companionship. Oh! I see you react negatively to that imperfect subjunctive.
Conclusion: Both La Chute and the Meursault, contre-enquête take the form of a confession to an anonymous listener whom the main character has met in a bar. The confession is spread out over a number of encounters. For this reason, the claim on Wikipedia that the narrative style in Daoud's novel is inspired Camus's La Chute is justified.