The URL of your Steady page always has this form: https://steady.page/publicationname. The short forms steady.de and steady.fm also work and redirect to the same page.
Old links with steadyhq.com automatically redirect to steady.page – more in “Steady’s new domain”.
Tip: You can force the page language via a language code in the URL, e.g. steady.page/en/publicationname. More about setting up your page: “Set up your Steady page”.