Hi,
I am trying to add a second recipient group to the marketing email. I am using dynamic content for this. My recipient field is as follows:

Which gives me an error:

I tried using a second field just like this:
​​​​​​​{{contact.contact_contact_ntt_alternativecontact.emailaddress1}}
In the body, it pulls the correct email through, but on the recipient field, it does not work and the main contact just gets the email twice.
How do I send the email to alternative contact?