Whether or not you need a VPN to play at 1Bet very much depends on your location. If you are located in the United States, for example, a VPN is likely the only way you’re going to be able to see the site, let alone register.
Whether or not this is advisable, is of course, up to you. Most online casinos overlook the use of a VPN as much as possible, though some are stricter than others. And should a VPN be detected your access could be blocked, with all that that entails. So the risk is really up to you.
In any event, if this is the route you choose, we strongly recommend choosing a good VPN service known to work well with online gambling. And to keep your login details straight, so you remember where you registered from, and to set your IP address accordingly.