State sales tax in the US is based on where the goods are delivered.
See the following from https://www.salestaxinstitute.com/sales_tax_faqs/foreign_visitor_sales_tax_refund
I am visiting from another country. Can I get a refund of sales taxes paid?
Generally, no refund of sales tax is available if you took possession of the item from the vendor with a given state. In the United States, sales tax is imposed at the point of transfer of title or possession. Therefore, if a non-resident visitor to the United States purchases any taxable items and takes possession of the goods at the retailer’s location, sales tax is due and there is generally no refund of the sales tax paid simply because the goods will be removed from the United States. The United States is different from many other countries that have a VAT structure, where it is more common to get this type of refund.
If the retailer ships the goods out of the United States to the non-resident’s location in another country, then the sales tax is generally not due. However, the retailer must export the goods and the customer cannot take possession of the goods in the United States.
and the following from https://help.cbp.gov/s/article/Article-373?language=en_US
The United States Government does not refund sales tax to foreign visitors. Sales tax charged in the United States is paid to individual states, not the Federal government - the same way that Value Added Tax (VAT) is paid in many countries.
If you are making a major purchase, such as a car, and you intend to export the item, you should contact the state taxation authority in the state where you will be making the purchase. They will be able to inform you of their criteria for refunding any sales tax paid.
