To use the API, you must get your personal API token. A token belongs to a user, and all user-rights (or limits) are applied to each transaction executed with the token.
From the settings menu in the top-right corner, select "API Token". Generate a new token. The token is displayed only once. If you lose the token, it can't be recovered. So store the token in a safe place.
The base URL of the API is
https://<server-domain>/api/v1. You must use HTTP basic authentication using your username and the API token as password.
Test the API connection by fetching the server status. Example:
curl -u john:740df110-8b06-4071-90c1-13645a023a85 \https://example.users.rport.io/api/v1/status