Each environment has a different API Key for authentication.
Create sandbox entities
Sandbox does not reserve or publish a fixed set of RFCs. When you create an entity, you can use any RFC that matches the format for its type: 13 characters for a person and 12 characters for a company. The dashboard can generate a valid-format RFC for you, and you can edit it before creating the entity. By default, sandbox assigns the entity a stable simulated fiscal profile. Tax status and applicable tax-return extractions reuse that profile so the generated records remain consistent across extractions. To select a specific profile through the API, addmetadata.sandbox.taxRegime to POST /entities:
metadata.sandbox.taxRegime when you do not need a particular profile.