Changes to API authentication

We've updated our Helcim API authentication to support header fields:

Field NameFormatDescription
account-idIntegerYour Helcim account ID. Learn how to find your Helcim account ID.
api-tokenStringYour Helcim API access token. Learn how to create an API access token.
const options = {
  method: 'POST',
  headers: {
    Accept: 'application/xml',
    'Content-Type': 'application/x-www-form-urlencoded',
    'account-id': '2301000123',
    'api-token': 'abced123456fghej'
  },
  body: new URLSearchParams({amount: '1.00', cardF4L4Skip: 0, ecommerce: 1})
};

This update is backwards compatible, as the Helcim API will continue to support the previous authentication fields of accountId and apiToken in the form body.