How to use the @sanity/webpack-integration/v3.getSanityEnvVars function in @sanity/webpack-integration

const compilationConfig = {
    env: 'production',
    staticPath: resolveStaticPath(workDir, config.get('server')),
    basePath: workDir,
    outputPath: path.join(outputDir, 'static'),
    sourceMaps: flags['source-maps'],
    skipMinify: !flags.minify,
    profile: flags.profile,
    project: Object.assign({}, config.get('project'), overrides.project)
  }

  await tryInitializePluginConfigs({workDir, output, env: 'production'})

  checkStudioDependencyVersions(workDir)

  const envVars = webpackIntegration.getSanityEnvVars({env: 'production', basePath: workDir})
  const envVarKeys = Object.keys(envVars)
  if (envVarKeys.length > 0) {
    output.print(
      '\nIncluding the following environment variables as part of the JavaScript bundle:'
    )
    envVarKeys.forEach(key => output.print(`- ${key}`))
    output.print('')
  }

  const compiler = getWebpackCompiler(compilationConfig)
  const compile = promisify(compiler.run.bind(compiler))
  let shouldDelete = true

  if (outputDir !== defaultOutputDir && !unattendedMode) {
    shouldDelete = await prompt.single({
      type: 'confirm',