Mathematical assignment

it is running but cant understand why cant level up?
whats missing?
please help

Use the += mathematical assignment operator to increase the value stored in levelUp by 5 .

levelUp = 10;
levelUp += 5;
console.log(levelUp);

Which challenge is this?

Can’t see any problem with the code, it should output 15. What value are you getting?

It could be because you’re missing a keyword in your declaration of levelUp.