So please I need your help how can I convince him
Before he spends the money on something stupid
Op if I may ask, why do you want to convince him to invest in Bitcoin when he is not interested in investing? do you want to force him so that at the end he will see you as the reason why he did not spend his money on what is best for him, I will suggest you let him do what is best for him so that you don't end up being the reason why he lost his money.
Bitcoin investment should be done by the determination and personal interest of the investor, do not force any one to invest and do not suggest the investment to anyone when they have no knowledge or likeness for Bitcoin and the investment.