Чтобы работало 

@can('create', Post::class)
  <!-- Текущий Пользователь Может Создавать Статьи -->
@endcan

@can('update', $post)
  <!-- Текущий Пользователь Может Редактировать Статью -->
@elsecan('create', $post)
  <!-- Текущий Пользователь Может Создать Новую Статью -->
@endcan

public function create(Request $request)
{
  $this->authorize('create', Post::class);

  // The current user can create blog posts...
}

Надо регистрировать политку

/app/Providers/AuthServiceProvider.php

<?php

namespace App\Providers;

use App\Models\User;
use App\Policies\Users\UserPolice;
use Illuminate\Support\Facades\Gate;
use Illuminate\Foundation\Support\Providers\AuthServiceProvider as ServiceProvider;

class AuthServiceProvider extends ServiceProvider
{
    /**
     * The policy mappings for the application.
     *
     * @var array
     */
    protected $policies = [
        'App\Model' => 'App\Policies\ModelPolicy',
        User::class=>UserPolice::class,
    ];

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

        //
    }

}

<?php

namespace App\Policies\Users;

use App\User;
use Illuminate\Auth\Access\HandlesAuthorization;

class UserPolice
{
    use HandlesAuthorization;

    /**
     * Determine whether the user can view the user.
     *
     * @param  \App\User  $user
     * @param  \App\User  $user
     * @return mixed
     */
    public function view(User $user, User $user)
    {
        //
    }

    /**
     * Determine whether the user can create users.
     *
     * @param  \App\User  $user
     * @return mixed
     */
    public function create(User $user)
    {
        //
    }

    /**
     * Determine whether the user can update the user.
     *
     * @param  \App\User  $user
     * @param  \App\User  $user
     * @return mixed
     */
    public function update(User $user, User $user)
    {
        //
    }

    /**
     * Determine whether the user can delete the user.
     *
     * @param  \App\User  $user
     * @param  \App\User  $user
     * @return mixed
     */
    public function delete(User $user, User $user)
    {
        //
    }


    public function before(\App\Models\User $user, $ability)
    {
        if ($user->isSA()) {
            return true;
        }
    }
}