Before using Laravel's encrypter, you must set a key option in your config/app.php configuration file. You should use the php artisan key:generate command to generate this key
No application encryption key has been specified.
Illuminate\Encryption\MissingAppKeyException
No application encryption key has been specified.
http://127.0.0.1:8000/
Your app key is missing
Generate your application encryption key using php artisan key:generate.
Copy .env.example to .env:
cp -a .env.example .env
Generate a key:
php artisan key:generate
Only then run:
php artisan serve
php artisan key:generate
php artisan config:cache