When you are setting up your trainer profile, the subdomain will pre-populate for you. Your subdomain is the text that is listed before 'fitterapp.app' in your unique URL, so the subdomain would be 'yourname' in 'yourname.fitterapp.app'.

You can update your subdomain by visiting your app settings and expanding the 'name & icon' section. If you would like to update your subdomain, please do so before launching your app and sharing with subscribers as this forms part of your unique web address and any previous subscribers will lose access.