Fdo you have the domain as suffix enabled in the domain settings?
Fif you disable that you should be able to set those emails in the username
FAnd what are you trying to do exactly? Do you get an error or what is the behaviour you get and don't want?
Fdid you add gmail as a domain on the organizatin?
Fin that case it won't work
Fyou only have to register a domain when you want specific organization domain such as organization-a.com in an organization
Ffor domain discovery this allows zitadel to identify where a user would belong
Fbut if you have multiple organization allowing gmail.com you anyway need to tell zitadel where a user should register