How do you add the custom class names to custom elements?

I created an ultra-basic custom element. All it does is echo Rank Math breadcrumbs.

That’s working fine.

I added a custom class and some custom CSS. That works fine in Bricks. It doesn’t work in browser.

After some digging, I realized that the custom class isn’t being output.

What is the proper way to wrap my output with classes added via Bricks Builder?

Thanks!

Looks like the answer is:

echo “<div {$this->render_attributes( ‘_root’ )}>”
// your content
echo “”;