We have finally been able to enable self-service registration of user accounts on the XMPP server. This is a a form on the web page with robot protection to prevent the creation of spam accounts. The service does also include functionality for self-service password resets. Please find the forms in the menu.
This service is based on the excellent plugin by Krzysztof Grochocki, for more information see here: https://wordpress.org/plugins/ejabberd-account-tools/