laravel unit test Invalid JSON was returned from the route

i wrote this unit test for login for laravel

class LoginTest extends TestCase
{

/** @test */
    public function auth()
    {
       $this->withoutMiddleware();
    $this->visit('/login')
        ->post('/login', ['example@example.com', "password"=>"1234"])
        ->seeJson([
            "login"=>"true"
        ]);
    $this->get('/dashboard');

}

}

but i get this error

Invalid JSON was returned from the route. Perhaps an exception was thrown?

how i can solve this issue ?

via flower