I think it seems to be impossible to open an online casino without license because for sure people will choose to get engage into an online casino which showcases legitimacy which can only be shown by having a license to prove that it is a legit and reliable one. Anything running or operating without license can be considered as illegal. If you do want to run an online casino then it is best to fix legalities first so that people will be attracted and want to get into your online casino. Although your objective was clear and precise to provide license once your website gets lots of players, still people do want to secure their own safety since online casino is a convenient way to play casino even at home that still uses monetary like the usual casino to play. It will be best to show that your online casino is legit by having license first before any other thing.