In Laravel you can easily add 404 page because Laravel already has 404 functionality.
What you have to do
You have to creates a new folder “errors” in resources/views/
After that create a file name 404.blade.php and put in to this new folder
Now its look like this
/resouces/views/errors/404.blade.php
You can add as per design in this 404 page you want.
Now you can check by entering any wrong work in your website URL this 404 page will come.