A weird Error object is being logged to console

I am trying to post comments through the youtube API, but they are returning an error upon trying.

When I log the error object I get

{ [Error: Bad Request] code: 400 }

The first part of which looks weird (key-value inside array?)

I tried to log the keys of the object and it only returns code

Supposely the API return a much more detailed message, but it's like it's 'hidden' inside the [Error: Bad Request], which I dont know how to access