I need an address for my trade in as they haven’t sent me a shipping label

You should contact Apple Sales support for help in getting that shipping label. The information below is from this link:

Contact - How to Contact Us - Apple

Apple Online Store

Apple.com is a convenient place to purchase Apple products and accessories from Apple and other manufacturers. You can buy online or call (800) MY–APPLE (800–692–7753).

You can get information about an order you placed on the Apple Online Store through the Order Statuspage. If you prefer, you can also get order status or make changes by phone at (800) 692–7753.

The return label for the trade is usually directly under the shipping label on the box. It's a 2 layer label. You should be able to tear the top label off with ease.