How to add a buyer to a lead?

video1.0<iframe src="https://www.loom.com/embed/d9aca5dc8261456b962e007b1b279010" frameborder="0" width="1532" height="1149" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe>11491532Loomhttps://www.loom.com11491532https://cdn.loom.com/sessions/thumbnails/d9aca5dc8261456b962e007b1b279010-b19d9b1f6c318e89.gif207.851How to add a buyer to a lead?