Can I trade in my old iPad Air for an Apple gift card?

I want to trade in my old IPad Air in for an apple gift card. I have since begun the steps to doing so, by erasing all data and disconnecting find my IPhone/IPad from all devices. Now that it’s all done, I don’t know what to do next to get my Trade in Kit. Does anybody know how to get one without buying something?

[Re-Titled by Moderator]