You can do that during the ticket buyer check out process. There are two possible options.
In your OTS dashboard, check distance based on credit card zip code.
Ask the ticket buyer for their location and check their location when adding their tickets to the cart. This requires the ticket buyer to share their location on the browser.
In this example, 'location sharing required' is selected. If a ticket buyer attempts to purchase outside of the radius, they will get this error:
