Tutorial should include custom function for get_avatar_url, too

I followed the https://metabox.io/create-custom-avatar/ tutorial, but found that the avatar only displayed in some places on my site even though the get_avatar function was used to display it. However, creating a custom get_avatar_url function as well, seemed to fix the problem and now the avatar displays correctly wherever it should.

This is the code I ended up using:

add_filter( 'get_avatar' , 'my_custom_avatar' , 1 , 5 );
function my_custom_avatar( $avatar, $id_or_email, $size, $default, $alt ) {
    
    $url = my_custom_avatar_url( $avatar, $id_or_email, $size );

    if (!empty($url)){
        $avatar = "<img src='" . $url . "' class='avatar avatar-" . $size . " photo' alt='" . $alt . "' height='" . $size . "' width='" . $size . "' />";
    }

    return $avatar;
}

add_filter( 'get_avatar_url' , 'my_custom_avatar_url' , 1 , 3 );
function my_custom_avatar_url( $avatar, $id_or_email, $size ) {
    $user = false;
    if ( is_numeric( $id_or_email ) ) {
        $id = (int) $id_or_email;
        $user = get_user_by( 'id' , $id );
    } elseif ( is_object( $id_or_email ) ) {
        if ( ! empty( $id_or_email->user_id ) ) {
            $id = (int) $id_or_email->user_id;
            $user = get_user_by( 'id' , $id );
        }
    } else {
        $user = get_user_by( 'email', $id_or_email );
    }

    if ( $user && is_object( $user ) ) {
        $value = rwmb_meta( 'user_avatar', array( 'object_type' => 'user' ), $user->data->ID );
        if ( $value ) {
            $avatar = $value['url'];
        }
    }    
    return $avatar;
}