About prototype in JS

I’m doing the challenge: Change the Prototype to a New Object
Link: https://learn.freecodecamp.org/javascript-algorithms-and-data-structures/object-oriented-programming/change-the-prototype-to-a-new-object/
Its easy to just follow the guide and finish the task like thisimage

and then I change to ES6 style like this and it still run well :))

but after i change to put prototype in an object like the guidance, it turns out like this

Can anyone help me with this issue :frowning:
Tks anyway !!

I’ve seen this kind of error before when webpack is configured differently – usually meaning they’ve restricted ES6 to strict mode: http://docs.w3cub.com/javascript/strict_mode/