To fix the Laravel error 419 session expired:
1. CSRF token verification failure
2. Session expired error due to cache
Sometimes, the cache can also lead to session expired error in front-end. This can be both the server cache and browser cache.
php artisan cache:clear
3. Laravel file and folder permissions
Similarly, improper file or folder permission can also lead to errors. Usually, web servers need write-permissions on the Laravel folders storage and vendor. Also, session storage needs write-permission.
chmod -R 755 storage
chmod -R 755 vendor
chmod -R 644 bootstrap/caches
Mostly, this fixes the error.
Hope it helps!!