yarn install throws an error when trying to install vanilo e-commerce for laravel

I am trying to install Vanilo E-Commerce. The link will take you directly to the yarn stage of the deployment.

I have updated my /var/www/laravel/e-commerce/evosmedia.uk/webpack.mix.js to the corresponding installation.

const mix = require('laravel-mix');

/*
 |--------------------------------------------------------------------------
 | Mix Asset Management
 |--------------------------------------------------------------------------
 |
 | Mix provides a clean, fluent API for defining some Webpack build steps
 | for your Laravel application. By default, we are compiling the Sass
 | file for the application as well as bundling up all the JS files.
 |
 */

mix.js('resources/js/app.js', 'public/js')
    // Add these 2 lines:
   .js('vendor/konekt/appshell/src/resources/assets/js/appshell.standalone.js', 'public/js/appshell.js')
   .sass('vendor/konekt/appshell/src/resources/assets/sass/appshell.sass', 'public/css')
    // Keep this for the "rest" (usually public frontend)
   .sass('resources/sass/app.scss', 'public/css');

When I run the command stated:

root@vps703141:/var/www/laravel/e-commerce/evosmedia.uk# yarn install

The error I get is:

/usr/share/yarn/lib/cli.js:46083
  let {
      ^

SyntaxError: Unexpected token {
    at exports.runInThisContext (vm.js:53:16)
    at Module._compile (module.js:374:25)
    at Object.Module._extensions..js (module.js:417:10)
    at Module.load (module.js:344:32)
    at Function.Module._load (module.js:301:12)
    at Module.require (module.js:354:17)
    at require (internal/module.js:12:17)
    at Object.<anonymous> (/usr/share/yarn/bin/yarn.js:24:13)
    at Module._compile (module.js:410:26)
    at Object.Module._extensions..js (module.js:417:10)

How can I include the CSS and JS for Vanilo?

via Chebli Mohamed