JavaScript. Does not respond to breakpoints, how to specify them correctly?

Question

JavaScript

I use slick slider

$('.product-slider_nav').slick({
          slidesToShow: 4,
        slidesToScroll: 1,
        arrows: true,
        focusOnSelect: true,
        prevArrow: '<div class="slider-arrow slider-arrow_left"></div>',
        nextArrow: '<div class="slider-arrow slider-arrow_right"></div>',
        asNavFor: '.product-slider_for',
        responsive: [
        	{
        		breakpoint 600,
        		settings: {
        			slidesToShow: 2,
        			slidesToScroll: 1,
        			arrows: true,
        			focusOnSelect: true,
        			dots: true
        		}
        	}
        ]
        });

The panel displays the following:

Picture

, which is very clear to me. That he does not UNDERSTAND that I indicate after the colon. How to do it right? Much needed for adaptation.

Answer 1

breakpoint: 600,
no colon