I'm trying to upload a page made in wordpress to a host but when modifying in settings leave the wordpress installation on the server and the url will leave it on the localhost by mistake 
As in the image, I need to know in which file that configuration is found
You find that in the database inside the table wp-options > siteurl and home, in your database editor or by means of command assign the url or otherwise insert in your functions.php:
update_option( 'siteurl', 'http://example.com' );
update_option( 'home', 'http://example.com' );
Or in your wp-config:
define('WP_HOME','http://example.com');
define('WP_SITEURL','http://example.com');