Why dots are not displayed in owl-carousel?

Question

css

codepen I've been scratching
my head for an hour why dot navigation doesn't work. I connect owl.carousel.css, owl.theme.default.css and owl.carousel.js, in carousel options I pass:

$(".owl-carousel").owlCarousel({
      items: 3,
      nav: true,
        dots: true,
        loop: true,
    });

But it turns out like this:

Neither buttons nor navigation dots are displayed. Looks like the styles are not being applied, but why? Tried both locally and on codepen . Help, pls.