The Orders endpoints are required to complete the Zip checkout flow.
Base URLs per Region
Production - US - https://api.us.zip.co/
Sandbox (Test) - US - https://api.sand.us.zip.co/
Production - CA - https://api.ca.zip.co
Sandbox (Test) - CA - https://api.sand.ca.zip.co/
Production - MX - https://api.mx.zip.co/
Sandbox (Test) - MX - https://api.sand.mx.zip.co/