Sales tax
https://smallbusiness.chron.com/tax-outofstate-purchases-20811.html
https://www.avalara.com/us/en/blog/2018/11/how-to-handle-sales-tax-on-shipping-a-state-by-state-guide.html
Google is great.
you do have the option to not use them ....
Sales tax is a pass-through tax. This means customers, not businesses, pay sales tax. However, business owners must collect, deposit, and report the sales tax.
Businesses that need to collect sales tax must do so at the point of sale. Customers purchasing products are responsible for paying the sales tax.
States can also get specific about which products have sales tax. For example, some states charge taxes on groceries while others do not.
https://www.patriotsoftware.com/blog/accounting/sales-tax-laws-by-state/https://smallbusiness.chron.com/tax-outofstate-purchases-20811.html
https://www.avalara.com/us/en/blog/2018/11/how-to-handle-sales-tax-on-shipping-a-state-by-state-guide.html
Google is great.
you do have the option to not use them ....