Do I need to include my Charger with MacBook Pro Trade In?

No. See the following from Apple Trade In - Apple

Do I have to include accessories like chargers and cables?

No, you do not need to include accessories. If you choose to include any, we will recycle them for you.

EverZen wrote:

Do I need to include my Charger with MacBook Pro Trade In?

I see nothing in the process https://www.apple.com/shop/trade-in

or

in the link https://support.apple.com/en-us/HT211018

that mentions the charger....

if you still have a reservation about the issue—Call Customer Support (800) MY–APPLE (800–692–7753)