Add "On Behalf of" option to Incident form and Portal

[Adil N]

Hi All, 

I am trying to improve our "Create Incident" form and the Record Producer "Create Incident". 

At the moment some customisation is done to add a tick box on the Incident form "Raise this for another person" (screenshot). I can remove this using "Configure > Form Layout" (see Screenshot Removed custom field) 

I want to add the OOTB feature for "Raised on behalf of". I tried this via form designer but it does not appear on the form. I also want to make sure when the record is produced via record producer it maps correctly. Any idea how I can 

1 - add the OOTB feature to my form & Record Producer 

2 - Ensure email notifications are configured so both the Raiser and the "Raised on behalf of" both get notifications 

Any steps to help will be much appreciated