What you have is a portal and in the relationship to that portal's table occurrence, "Allow creation of record via this relationship" has been enabled for that portal. Clear that check box and the blank "add row"--which would ordinarily be used to add new records to the portal without having to click a button to add the new portal record, will disappear.
Thank you Phil,
That did remove the blank row on new record request. However, after I removed the checkmark, my new items won't appear in my item list. My portal popup still works but and I can select the new item to be ordered but it doesn't show up . I'm send you another screenshot. Thank you for your support.
Did this work before you made this change at the relationship level?
If so, it would appear that a script is interacting directly with your portal row to create the new record by going to the last portal row and setting data in that row to a value or values.
You'll need to either put back the "create.." option or modify the script.
You might find the select product in popover examples in Adventures In FileMaking #2 a useful source of ideas.