Lets try this:
function slider_script () {
wp_enqueue_script( 'slider-js', get_stylesheet_directory_uri() . '/src/js/slider.js', array(), time(), true );
}
function add_type_attribute( $tag, $handle, $src ) {
if ( 'slider-js' !== $handle ) {
return $tag;
}
$tag = preg_replace("/(.*)(><\/script>)/", '$1 type="module"$2', $tag);
return $tag;
}
add_action('wp_enqueue_scripts', 'slider_script');
add_filter( 'script_loader_tag', 'add_type_attribute', 10, 3 );