Rebilly REST API

In the Rebilly app, go to API keys. Under Automations → Development → API keys, click Create API key, choose Secret, save it, then copy the key from the Key column. The API docs say server-side requests use the secret key in the REB-APIKEY header, and requests should include the organization in the URL path such as /organizations/{organizationId}/....

Rebilly's OpenAPI description lists JWT as a supported authentication method for the REST API, describing it as a short-lifetime token with a specific expiration time. The public docs scraped here do not show a self-service minting flow for developers, so use the Rebilly developer docs and account/app features to obtain or issue a JWT for your integration as supported by your account.