how to icrease admin session timeout

Sorry? Can you elaborate?

You can create a plugin to do this or find one that already exists.

If you’re feeling dangerous, you could add it to your template, although that can cause a whole new mess of problems.

The code would be something like:

function myplugin_cookie_expiration( $expiration, $user_id, $remember ) {
    return $remember ? $expiration : 600;
}
add_filter( 'auth_cookie_expiration', 'myplugin_cookie_expiration', 99, 3 );

Where 600 is the amount of time in milliseconds that you want before the session expires.

best of luck!

Take the backup of webroot directory and database.

Then install the plugins “configure-login-timeout” and increase the session time out,