Elementor posts custom query based on tag [closed]

Question

How can I filter the Elementor Posts widget with a custom php query that returns posts with a specific tag attached?

I want to do something similar to this:

function my_query_by_post_types( $query ) {
    $query->set( 'post_type', [ 'custom-post-type1', 'custom-post-type2' ] );
}
add_action( 'elementor/query/{$query_id}', 'my_query_by_post_types' );

The line that interests me is:

$query->set( 'post_type', [ 'custom-post-type1', 'custom-post-type2' ] );

But instead of querying post types, I want to query a specific Tag from the "Posts" post type. I'm not familiar with the syntax so I am not sure how to type it in.