KYC is recommended in almost every casino. Some casino sites it is done before betting and on some sites it can be done without kyc. But I think it is better for the gambler to complete KYC to conduct smooth betting. If KYC is not a problem for a gambler who bets small amounts, KYC should be done for big gamblers who gamble a lot otherwise there may be problem. If KYC is shared in terms and conditions then it must be completed prior to gambling. Many people neglect this, but if you get a big win, there may be a problem with the money of that win. So it is better to do KYC to avoid such problems.
So the conclusion is that it is better to do KYC at the beginning before gambling at the casino, because there are not a few incidents of people who won big wins then had to KYC but the data was rejected or had a long process, so before facing problems like it is better to do KYC at the beginning, of course in a place that is regulated and has a good license so that we feel safe at their casino, choosing the right casino is also a blessing in such cases.