Unfortunately, you can't run a casino without a license anywhere, even if it is a BTC casino.
But...
As you can see OP, unfortunately, there is also no possibility to ask for a license later when casino is already running and got decent traffic.
I understand OP concerns/questions because many BTC casinos work without a license and are pretty successful. BTC changed everything and also has a lot of impact on the gambling industry.
To be honest, there are many jurisdictions were obtaining a gambling license is much easier and many times casinos open their business in these countries.
The main problem for FIAT online casinos were payment processors. They will not cooperate with any casino without a license and here comes BTC with help.
Today one could argue if a license for BTC casino is needed at all?
There is no need for payment processors because of BTC, so the main problem is resolved. Additionally, BTC is much better as FIAT because it is much more anonymous and payments are very fast compared to any payment processor. "On the other hand, a lot of players think about Bitcoin casino in the same way as any traditional online casino. They want to be sure that they bring their BTC to a reputable and secure online environment and that their rights are protected by an independent authority. In this case, a valid gambling license from one of the gaming licensing jurisdictions becomes an important marketing tool that contributes to player loyalty and considerably increases the casino’s reputation".
To summarise everything OP could easy-open a BTC casino without a license and make it operational. The important thing is that licenses cost a lot of money and time which is a huge entry barrier. The licensing process is not easy because of requirements, costs, taxation policy and application processing time. Casino software has to meet the requirements of the jurisdiction. Licensing bodies in different jurisdictions pose various requirements to the software used by the casino. Incorporate a legal entity in the required jurisdiction, certificate of no criminal record from the police and much more.
Here all jurisdictions which issue gambling licenses.
https://www.softswiss.com/licensing/
https://www.softswiss.com/licensing/
https://www.softswiss.com/knowledge-base/how-to-get-gaming-license/
https://www.softswiss.com/knowledge-base/is-bitcoin-gambling-legal/