Ok, suddenly the casino you're playing asks you for proof of income to be able to withdraw your winnings and to keep your account in good standing, your bankroll every month is $500 and you provide proof of salary that you are making $500 net every month, will they accept that proof will they accept that you are putting all your salary for gambling, will this violate the principle of gamble for fun, because you are working to gamble based on your proof income.
An automatic deduction of a certain amount from my payroll to the gambling website? This is absurd and I doubt that anyone would agree to this kind of setup. This is not only potentially dangerous but you are putting yourself in a situation where you are digging a grave. Instead of allocating a portion of your income to gambling, it is better that you explore other modes of entertainment.
This kind of situation contemplates a system where the gambler can monthly fund their earnings on the website. This will most likely result to a destructive and dangerous outcome since the gambling website is creating an addiction to the user.