Gatsby Cloud environment variables not working in production

In a Gatsby project hosted in Gatsby Cloud I'm passing an API key as an environment variables, but unfortunately it's not available...

The code looks like this:

import React, { useEffect, useState } from 'react';
import Airtable from 'airtable';

Airtable.configure({ apiKey: process.env.AIRTABLE_API_KEY });

const base = Airtable.base('appKjIv7utFmqAkdT');

function Gallery() {...

You can see where I'm inserting the API key.

My gatsby-config.js looks like this (I'm loading dotenv on top):

require('dotenv').config({
  path: `.env.${process.env.NODE_ENV}`,
});

module.exports = {
  siteMetadata: {
    title: `wernergeller.com`,
    siteUrl: `https://www.yourdomain.tld`,
  },
  plugins: [
    {
      resolve: 'gatsby-plugin-google-analytics',
      options: {
        trackingId: '123',
      },
    },
    'gatsby-plugin-image',
    'gatsby-plugin-sitemap',
    'gatsby-plugin-sharp',
    'gatsby-transformer-sharp',
    {
      resolve: 'gatsby-source-filesystem',
      options: {
        name: 'images',
        path: './src/images/',
      },
      __key: 'images',
    },
  ],
};

Locally (gatsby develop) this is working well.

Any help is highly appreciated!

In Gatsby Cloud variables needs to be added in the dashboard. The URL is something like: https://www.gatsbyjs.com/dashboard/YOUR_ORGANIZATION_UUID/settings/general#env-vars

And visually:

You can add variables individually or in a bulk with key:value pair:

Keep in mind that if you have environment variables that need to be accessed in the browser rather than the server, you'll need to prefix with GATSBY_.

It looks that the Airtable configuration is set on the browser, so you will need to change the key to:

Airtable.configure({ apiKey: process.env.GATSBY_AIRTABLE_API_KEY });

Changing the environment variable accordingly in the process.env and in the Gatsby Cloud dashboard.

Test your site with gatsby build locally before pushing it because gatsby develop it's not a full representation of your built/compiled project.