You are only required to mail this form if you claim the Developmentally Disabled Credit (AR1000RC5) or the Other State Tax Credit. If you claimed either of the mentioned, you will mail the form along with the proper documents to the following address:
Arkansas Electronic Filing Group
P.O. Box 8094
Little Rock, AR 72203-8094
or email to AR8453@dfa.arkansas.gov
If none of the above applies to you, you would just sign the form and keep it for your records. Per the instructions for the from "If you choose to file your State of Arkansas tax return by using one of the online web providers, you are required to complete AR8453-OL. You must keep the completed and signed AR8453-OL along with your tax return and any W-2's and/or 1099's."