React .env.environment file's variable not working

I connected my react app with Contentful's database. When I give the access key directly, it works fine. But when I give an access key in .env.environment file, the variable does not work.

contentful.js file:

import {createClient} from 'contentful';

export default createClient({
  space: process.env.REACT_APP_API_SPACE,
  accessToken: process.env.REACT_APP_ACCESS_TOKEN
});

.env.enviroment file:

 REACT_APP_API_SPACE= my access key
 REACT_APP_ACCESS_TOKEN= my access token

Console error:

Uncaught TypeError: Expected parameter accessToken
at createClient (contentful.node.js:7563)
at Object.<anonymous> (Contentful.js:3)
at __webpack_require__ (bootstrap fafcbb2b670a4f50dfbb:555)
at fn (bootstrap fafcbb2b670a4f50dfbb:86)
at Object.<anonymous> (context.js:5)
at __webpack_require__ (bootstrap fafcbb2b670a4f50dfbb:555)
at fn (bootstrap fafcbb2b670a4f50dfbb:86)
at Object.<anonymous> (FeaturedRooms.js:2)
at __webpack_require__ (bootstrap fafcbb2b670a4f50dfbb:555)
at fn (bootstrap fafcbb2b670a4f50dfbb:86)

But it works fine when I give the access key directly in my contentful.js file like this:

import {createClient} from 'contentful';

export default createClient({
  space: my access key,
  accessToken: my access token
});

As I am uploading to Git, I don't want to give the key directly.