import Benny from '@bennyapi/sdk';

const client = new Benny({
  subdomain: 'My-Subdomain',
  apiKey: process.env['BENNY_API_KEY'], // This is the default and can be omitted
});

const response = await client.payment.reverse();

console.log(response.retrievalReferenceNumber);

{
  "retrievalReferenceNumber": "<string>"
}