How to Convert HTML PHP MYSQL Website To WordPress Website in 20 Minutes

hi, I would to ask, why do all links on my Wordpress site show me the homepage? If my code like below, it will show the correct page.:
if ($_SESSION['user_role'] == 'administrator') {
echo '<script>window.location.href="wp-content/themes/mycustom/admin/dashboard.php";</script>';
} else if ($_SESSION['user_role'] == 'user') {
echo '<script>window.location.href="wp-content/themes/mycustom/user/dashboard.php";</script>';
}

But if my code like this:
if ($_SESSION['user_role'] == 'administrator') {
echo '<script>window.location.href="admin/dashboard.php";</script>';
} else if ($_SESSION['user_role'] == 'user') {
echo '<script>window.location.href="user/dashboard.php";</script>';
}

it doesn't not work. When I click on any link on my WordPress site it loads homepage, but link URL changes on the address bar. What could be wrong and how can I fix it?

Wow sir great video make more and easy custom coding in WordPress PHP

just stop, horrible

can i edit this page afterwards using wordpress elementor

Bro can you make website like codashop

Plz send me your what's ap number

source code

1st