If you owe tax due to the state then the voucher should print out with the state return when you print it.
https://ttlc.intuit.com/community/printing/help/how-do-i-print-and-mail-my-return-in-turbotax-online/00/26258
You must pay your state tax due using the state’s preferred method of receiving payment. For most states that will be by making a payment to the state’s own tax website, or by mailing a check or money order.
https://ttlc.intuit.com/questions/1901670-how-do-i-contact-my-state-department-of-revenue