It should be there but you can add it yourself as well – it’s a boolean. You could also download the module package again (5.1 introduction) to double check how it’s supposed to be.
I just opened the package listed in the introduction (6.1) and found this domain model (which does include the HasAccount attribute on the bottom of the Employee entity):
You can either download that module package (though I think you’d need to redo some previous steps) or (perhaps simpler) add the HasAccount field to the entity yourself (and add the checkbox to the page yourself).
HasAccount is boolean type attribute, a part of Employee entity, so it is a radio button, u need to add it in the entity, or you can download module package and check how they have configured the attribute in the entity