1. Turn on Business: Cart > Enable Custom Tax Calculation Systems.
2. In Integrations, open the TTR Tax card; on its Colorado TTR row paste the TTR API Key (a bearer token from the TTR developer portal, developer.ttr.services) and pick the States to activate TTR for. Alternatively pick TTR - (Colorado API) on each state's edit page.
3. Whenever a customer saves a delivery address (or you save a pickup location) in an activated state, Sprwt asks TTR which tax jurisdiction the address belongs to and caches the jurisdiction and its rate.
4. At checkout the cart uses the cached rate for that address. If the address has not been resolved yet, the normal zip-code / state tax applies.
5. A monthly scheduled job re-fetches jurisdiction rates for every activated state so cached rates stay current (throttled to roughly once every 30 days).

TTR is queried for the "Food for home consumption" product category, so exempt jurisdictions come back as no-tax.