[widget]Add weather widget in the sidebar by using code

Hello all,
I’m trying to add a widget in my sidebar, the problem is that the primary area and the secondary area contain widget, and i use the following codes for displaying them:

<?php if ( ! dynamic_sidebar( 'primary-widget-area' ) ) : ?>

<?php endif; // end primary widget area ?>

<?php dynamic_sidebar( 'secondary-widget-area' ); ?>

i want to add the third widget in the same way, but i hadn’t the third area in my backoffice 🙁

is there any code that can allow me to add my widget in sidebar.php?

I really need your help, thank you in advance