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.createMethod({
  externalUserId: 'externalUserId',
  mask: 'mask',
  tokenId: 'tokenId',
});

console.log(response);

{
  "code": "BAD_REQUEST",
  "message": "Invalid input parameters"
}