Source

File: wp-includes/theme.php

function get_stylesheet_uri() {
	$stylesheet_dir_uri = get_stylesheet_directory_uri();
	$stylesheet_uri     = $stylesheet_dir_uri . '/style.css';
	/**
	 * Filters the URI of the current theme stylesheet.
	 *
	 * @since 1.5.0
	 *
	 * @param string $stylesheet_uri     Stylesheet URI for the current theme/child theme.
	 * @param string $stylesheet_dir_uri Stylesheet directory URI for the current theme/child theme.
	 */
	return apply_filters( 'stylesheet_uri', $stylesheet_uri, $stylesheet_dir_uri );
}