A lead can be created by a form submission through the Form Actions.

The CRM element needs to be used in the form template to have the lead create, however, you can have an action to also create the CRM Contact, in your actions. This will need to be the first action as the lead creation will need to have the contact created before creating the lead. 

If having the contact created as part of the form action, ensure that is prioritised to happen before the lead is created.