Hi Missy,
I am glad you are taking two trips in a year and can take advantage of the
Annual Pass. This allows you the flexibility to experience more of the magic of the Walt Disney World Resort.
You are correct that you will need the physical ticket to have the discount. However, the resort may take the voucher. Upon checking in, ask the cast member if they will accept the voucher. If so, you are good to go.
If not, no worries. Simply have the voucher converted. You can do this at any of the four parks or at Downtown Disney. Simply drive to the nearest location or hop on a bus to obtain your ticket. You could even stay and play prior to heading back to check in.
Then take the ticket with you upon completing check in and you are all set.
Wishing you a magical vacation!
Beth