I'm trying to use Environment Variables via plugin method (https://docs.cypress.io/api/plugins/configuration-api#Switch-between-multiple-configuration-files), this has worked previously but recently has stopped working for me, any pointers would be great.

plugin/index.js

const fs = require('fs-extra')
const path = require('path')

function getConfigurationByFile(file) {
  const pathToConfigFile = path.resolve('cypress', 'config', `${file}.json`)

  return fs.readJson(pathToConfigFile)
}


module.exports = (on, config) => {

  const file = config.env.configFile || 'build'

  return getConfigurationByFile(file)

}

ConfigFile > build.json

{
    "env": {
        "StudentPortal": "https://www.google.co.uk"
    }
}

Usage

cy.visit(Cypress.env('StudentPortal'));

As I said, this used to work and would visit the URL within the configFile, now I just get the following error:

CypressError cy.visit() must be called with a url or an options object containing a url as its 1st argumentLearn more cypress/support/commands.js:17:8

15 | Cypress.Commands.add('StudentPortalLogin', (email, password) => { 16 |

17 | cy.visit(Cypress.env('StudentPortal'));