I am having a hard time with an automation for updated record. Right now my Assignee field allows for multiple collaborators on our team to share records. Sometimes a record will need to change from the original assignee and be reassigned to another collaborator(assignee). What I need is for Outlook to send an email to the person that the record has been reassigned to. I keep trying to address it but keep getting notified by Airtable that the automation didn't work (Failed to construct the value for "To").

The “assignee field” is called Agent Lead Owner. 
Outlook is already integrated.

I have attached an image for reference. Hopefully someone understands what I am trying to achieve here and can help me out.

Thanks,
Lena