I worked for a company where we hosted some stuff in China (on Alibaba Cloud) and we had to register there and get an ICP number (it stands for Internet Content Provider). It's obligatory to display it somewhere on the page.

Looking at Kraken contributors, they work for Alibaba, so it seems they host that website in China.

Yeah. All public websites need to be registered with the the government and are assigned a BeiAn code. It's a link to the registry where you can find who owns and operate the website with the code listed.