What is the promo code thing about?

[A the Great_1]

I do not understand where you can get the promo code for the boss coins. Furthermore, what is the promo code?? Please answer as soon as possible.

[DE XRIST]

@a-the-great_1
Hello mate, promo code can be a single word on a phrase that a manager can use to earn some more boss coins...from time to time promo codes are introduced/revealed via the social media of the game....you have just to follow the media and maybe you can get lucky....