I sent an email to support. Their support email address is written somewhere on their website. I sent them multiple emails from multiple email providers over the last few months. They don't reply support emails.
In order to join the chat, you need to be registered user. In order to be registered user you need to use their preferred email providers. They probably force their users to have gmail or something similar. They don't accept any email address.
They are not active here anymore it seems. It is a big problem for the user not to reach the contact support to report their problem and I think they should be improved it but it looks like they're nowhere to be found I think you should just create google account to send them a message if you really want to reach them. Now I appreciate the live contact supports on the gambling site on where I play in.