Trade in value

You can get an estimate directly online, but will need to send it in to get a final value for your device.

Brightstar (Apple's partner for trade in and recycling of devices) is known to have issues with devices sent in to them for evaluation: what is brightstar? - Apple Community

You can set up the trade in during purchase on the Online Apple Store. Or perform the trade in before buying a new device using the Trade in portal.

No such thing. “Third party” like Brightstar, really determines trade in value, not Apple. Had plenty people in this forum complaining about trade ins being rejected because issues with Brightstar. Click this link and read: https://www.apple.com/shop/trade-in