Hello there, that is online gambling and you should have a gambling license if you are planning to build a gambling website. This certificate/license will prove to the authority that your are operating gambling in a legal way. Because there is a regulation of all types of online gambling platforms [1] here, Gambling Commission. So you need some paper works and this article might help you [2] here, Online Gambling License – How To Get It?.

Anyway, that is too much workload you must need other staff. I hope that the article may help you.