Assalamu alaikum,

Thank you for your inquiry.

Gambling is forbidden in Islam. It is stated in the Quran:

O you who believe, alcohol, gambling, sacrificial stones and divination arrows are an abomination and the work of Satan. Avoid them, that you may prosper! Satan only desires to sow enmity and hatred between you by alcohol and gambling, and to keep you away from the remembrance of God and from prayer. Will you not then desist? (5:90-91)

It doesn’t matter that the money goes to charity.

And Allah knows best Najeeb Naz