Do you already have the federal Business program? You buy the state from inside the federal program. You can't buy it separately.
Business program State Forms Availability
https://care-cdn.prodsupportsite.a.intuit.com/forms-availability/turbotaxbusiness_states.html
How to download the Windows state program,
https://ttlc.intuit.com/turbotax-support/en-us/help-article/product-delivery/download-turbotax-state...
