where is service number for Microsoft device repair order located?

Hi I just made a Microsoft Xbox device warranty repair for Xbox controller core 2. And the shipping instructions says, "put service number outside box". But i can't find it in my emails, website, agent, service page. there is just an order number & serial number on the site & in the service repair request email sent to me. Is there a service number? where is it located? is it the same as order #? because thats all i can find but its already on the shipping label. please help

:)