he can run a casino without license but no credibility. just look at the gambling section. there are several casinos, dice sites or betting platforms that have no license yet. not even the curacao gaming license. and yet they are operating. only those gamblers that want to risk will play on that site. or they will try playing, but they will deposit small amount of money. and that is understandable for a substandard casino.
so i dont think the OP can attract traffic before acquiring his license. that only shows that he has no sufficient funds to hold this kind of business.