[5] On 7 January 2024, Mayulu made his professional debut for PSG as a substitute in a 9–0 Coupe de France win over Revel in the round of 64.

[6][7] Five days later, PSG announced that he would integrate the first team as part of the "elite group", joining teammates Ethan Mbappé and Warren Zaïre-Emery.

[8][9] In the round of 32 of the Coupe de France on 20 January, Mayulu scored his first professional goal, a lob over the goalkeeper in a 4–1 victory against Orléans.

[11] On 6 April, he started his first senior match against Clermont;[12] he went on to score a goal that was later disallowed by VAR due to a foul by his teammate in the build-up.

[13] On 24 April, Mayulu made his second start for PSG in a match against Lorient, providing his first career assist for Ousmane Dembélé's opening goal in a 4–1 victory.