import Telnyx from 'telnyx';

const client = new Telnyx({
  apiKey: process.env['TELNYX_API_KEY'], // This is the default and can be omitted
});

const numbersFeature = await client.numbersFeatures.create({ phone_numbers: ['string'] });

console.log(numbersFeature.data);

{
  "data": [
    {
      "phone_number": "<string>",
      "features": [
        "<string>"
      ]
    }
  ]
}