A lure is not an attack on its own, but most attack types can have a lure attached to them in the Attack Settings. Lures prepare the targets of a phishing campaign for the phishing email, lowering the user's guard and tricking them into believing that the email is real.
Checklist
Lure Emails
First enable the Double Barrel Attack setting, set a delay, and save:
The delay is in seconds, so 1800 seconds is 30 minutes between the lure and the attack.
Then go to the Lure Template tab and create a lure email: