I don't know about other servers, but do this if you are looking to have your account on the genzedong server.
Open the Element app, or one of it's forks. Get to the sign-up page, where you'd be requested to choose your sever. It will default to matrix.org, but below that, you'll have the option to add a different server than that. After choosing that option, enter the address: genzedong.xyz
You then choose your username and skip the option to add an e-mail address to your future account. After these you should land in your account. Then you have to follow the steps to be a verified new member, by either answering the questions listed in one of the visible rooms or messaging the admin of your choice, telling them your Lemmygrad username. After a little waiting, you are hopefully approved and are able to use your account without an added e-mail address.
For a more detailed guide, look for the matrix room ad in every week's general discussion.