Apple Watch trade in
Do I only send Apple Watch to apple or you want all accessories too?
Apple Watch Series 6, watchOS 8
Question marked as
No. Do not send the band or charging cable. See the 'Before you ship your Apple Watch' section in:
How to prepare your iPhone or Apple Watch for trade-in - Apple Support
"Remove the band from your Apple Watch. If it is included in the box, it will be recycled and cannot be returned to you."