Hidden "Last Name" field on delta.com

http://delta.com/login/loginPage uses an annoying progressively unhidden login form. The login requires three fields (Username, Password, and Last Name), but the Last Name field is initially hidden until the Username field is manually filled. I have saved all 3 fields to 1Password, but because the Last Name field is initially hidden the login form does not work
with 1Password's autofill feature completely.

So I end up having to press

Command+\
Enter
Command+\
Enter

to login to the website. Is there anyway to update 1Password so that it fills all 3 fields at once?

1Password Version: Not Provided
Extension Version: Not Provided
OS Version: Not Provided