Check file private and public keys before generate token

AuthServiceProvider.php

class AuthServiceProvider extends ServiceProvider
{
    /**
     * Register any authentication / authorization services.
     *
     * @return void
     */
    public function boot()
    {
        $this->registerPolicies();

        // Register the Passport routes
        Passport::routes();

        // Check the Oauth Key before set the token lifetime
        // This will help when you need to run "php artisan passport:install" on server production
        $privateKey = File::exists(storage_path('oauth-private.key'));
        $publicKey  = File::exists(storage_path('oauth-public.key'));
        if ($privateKey && $publicKey) {
            $server = $this->app->make(\League\OAuth2\Server\AuthorizationServer::class);
            $server->enableGrantType(new \Laravel\Passport\Bridge\PersonalAccessGrant(), new \DateInterval('P7D'));
        }
    }
}