I tried it using different IP's and it worked fine for me so I do not think it has regional restrictions.
Although the website is quite slow and laggy so that might causing the issue you are having. Try registering again with different email, it might work.
I have used several devices that have fairly high operating system characteristics, as well as various VPNs from different regions, but I still have a problem. Most likely, this resource has certain lags that should be eliminated by developers.
I am using this website and it does have lags, but I tried using ip's from different countries and I had no
problem using it, sometimes it does lags but it is not making it unusable.
It seems to me that the problem was in my mobile operator, which blocks certain resources for access. Even using a VPN did not help in this case, but when I changed the Internet provider, the problem was resolved and I achieved the desired result.