Hi there, each user needs to register on the relevant server (in this case KoBoToolbox - click on “create an account”). They create their own user account/username then verify their email address. Once they have a username then you can share the project with them by typing their username in to the box on Sharing screen and selecting what permissions they should have.
(If you were using your own server then there is a way to create users in bulk - and there is a feature request to perhaps allow bulk user creation via the web app in future - but for now that’s not possible Advanced user management: easily create and manage data collectors and admins - #29 by Josh )
