Once you have completed your 2018 Rhode Island state return and you print your documents you should see a payment voucher for Rhode Island. You must mail this payment voucher along with your payment to the address listed on the form. Please follow the directions in the TurboTax FAQ below to print your payment voucher.
https://ttlc.intuit.com/replies/3401713
You may also click the link below and pay your state tax due online instead.
https://www.ri.gov/app/taxation/payments