How do I extend my own entity

I have an entity Person and want to create another entity ContactPerson which extends Person. how do I implement this? On the Parent Class dropdown menu the entities I created do not appear there.

Have you seen this sample project: ? (Also available in Studio on the Samples tab).

Thank you

Hi Victor,

How many screens will you use, one for Person and one for ContactPerson ? In that case I will be interested by the way you designed the said screens, if you mind to share.