Sorry for the delay.

First you need to build an array for the switcher:

$switcher = array(
	
	'urls' => array(

		'fr' => false,
		'en' => 'https://',
	),
	'main' => 'fr',
);

Then update the 2 following post meta data:

update_post_meta( $post_id, 'lsw_language_switcher', $switcher);

update_post_meta( $post_id, 'lsw_main_language', $switcher['main']);

If you are editing a post that already has settings don’t forget to merge the previous array with the new one:

$switcher= get_post_meta( $post_id, 'lsw_language_switcher', true);

// add/modify english url

$switcher[urls]['en'] = 'https://';

update_post_meta( $post_id, 'lsw_language_switcher', $switcher);