How can I check if the logged in user has a "1" on the admin column in Laravel 5?

I'm wanting to only show links if the logged in user has a "1" on the admin column from the users table.

What I've tried:

In my User.php

public function isAdmin(){
     if(Auth::User()->administrator == 1){
        return true;
}else{
        return false;
    };
}

My migration:

 Schema::create('users', function (Blueprint $table) {
        $table->bigIncrements('id');
        $table->string('firstname');
        $table->string('lastname');
        $table->boolean('administrator')->default(0);
        $table->timestamp('email_verified_at')->nullable();
        $table->string('password');
        $table->rememberToken();
        $table->timestamps();
    });

My Blade:

@if(Auth::check())
  @if ()
    <a href="/admin">some link for admins only</a>
  @endif
@endif

The link doesn't show up no matter who logs in.

via Chebli Mohamed