Download part from thingiverse
Unfortunately not all product are designed to last a life time. This is the case for some of the lower-end NUMARK dj equipment. I have broken a total of 3 CUE buttons on my NUMARK MIXDECK controller. And now I have designed my own replacement button to save money, and hopefully to help other save money as well. The repair service I used cost me 80$ and to my surprise, when I disassembled the controller, they did not even replace the button unit, they just glued it with some hot glue. The replacement button it self is like 20$ incl. shipping. But this 3d model cost around 0.5$ in resin - probably even cheaper on PLA printers.
Official replacement part: https://instrumentalparts.com/button-painting-cue-large-pt1110636210/