To access API from your system you need to whitelist your IP and create access token. Use access token when sending call using Create order or Deposit methods.
Authentication token are created from customer cabinet. Customer ID is displayed in customer cabinet, under company name.
To add new access token please login to CityPay and move to developers page. On the page click on add new token button. Fill all mandatory fields, including IP white-list. By filling IP white-list field you will grant access to specific IP-s.