Please follow the original Start Wizard directions to add the Assessed Person and Add a Form: https://answers.aseba.org/post/new-assessment-wizard-for-adding-assessed-persons-and-forms
The Send Message to Informant process has been added to the end of the Wizard. Once you have set up the Assessed Person and the Form, the Wizard will ask:

Fill out the informant's email address and the reply to email address. Each blank is editable except for the From and Send a message template. When finished click Send.

Once you press the Send button, the status of your form will go from New to Sent to Informant.
