Task-oriented dialogue about: train

Can you find a train departing from Cambridge going to Kings Lynn? Thanks.
Absolutely! It looks like this is a 47 minute ride. What day and time are you looking to depart?
I want to leave after 21:00 on sunday.
I found a train for sunday after 21:00 leaving cambridge going to kings lynn. Would you like to book it?
Yes, please book it for 1 and send me a reference number.
The reference number is TVFAM55I .