wc_get_template new template does not showing up

plugin_dir_path( FILE ) will return the current directory.
Not sure where you call this q343_get_template() function if it’s on a subdirectory then plugin_dir_path( FILE ) is returning that subdirectory path.

From WordPress Code Reference https://developer.wordpress.org/reference/functions/plugin_dir_path/

The “plugin” part of the name is misleading – it can be used for any file, and will not return the directory of a plugin unless you call it within a file in the plugin’s base directory.

The safest way is to use define on your root plugin file.

define( 'MY_PLUGIN_PATH', plugin_dir_path( __FILE__ ) );

Then call the function like this

add_filter( 'wc_get_template', 'q343_get_template', 10, 5 );
function q343_get_template( $located, $template_name, $args, $template_path, $default_path ) {    
    if ( 'myaccount/orders.php' == $template_name ) {
        $located = MY_PLUGIN_PATH . 'required/templates/orders.php';
    }

    return $located;
}