The email templates are handled in your online account at https://helios.omnitapps.com. Log in and from the dashboard, go to "Requests" and select the "Email templates" tab.

You can either edit existing email templates or create new ones. Here you can edit parameters like your (company) name and the email subject. If you are knowledgeable about HTML you can also make a custom email body.

After setting up a new template you can select it in Omnitapps when choosing a mail template, for example under BrochureRequest>Email form.