Display custom content using page.php from theme

Adding and catching the query vars (wpex_page=confirm) is the simple part as explained in this answer but sine you want to use the theme’s default page.php there is something extra you need to do and this is a nice tutorial which covers it.

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)