At the first, you should check the url with a valid tools, like alexa:
https://www.alexa.com/siteinfo/8bet.ioon the alexa, you can see site rank And many details that can help you to know more.
Good luck
Alexa rank basically shows only the number of visits to the site and the origin of the people who visit the site. Based on this data, you can judge the popularity of the casino, but not its credibility.