Postman pre-request script to get a new JWT token before each request

postman.js

pm.sendRequest({
  url: pm.environment.get('url') + '/login_check',
  method: 'POST',
  header: {
    'Content-Type': 'multipart/form-data',
  },
    body: {
      mode: 'formdata',
      formdata: [
        { key: '_email', value: pm.environment.get('email') },
        { key: '_passwd', value: pm.environment.get('password') }
      ]
    }
  },
  function(err, response) {
    const jsonResponse = response.json();
    pm.environment.set('token', jsonResponse.token);
  }
);