why my test throws an error?

showing this error and first test is passing true why error :(

$ pf ProjectsTest
PHPUnit 9.5.26 by Sebastian Bergmann and contributors.

.EE                                                                 3 / 3 (100%)

Time: 00:00.886, Memory: 32.00 MB

There were 2 errors:

1) Tests\Feature\ProjectsTest::test_a_project_requires_a_title
Error: Object of type Tests\Feature\ProjectsTest is not callable

C:\laragon\www\birdboard-tdd\tests\Feature\ProjectsTest.php:34

2) Tests\Feature\ProjectsTest::test_a_project_requires_a_description
Error: Object of type Tests\Feature\ProjectsTest is not callable

C:\laragon\www\birdboard-tdd\tests\Feature\ProjectsTest.php:39

my test code

 public function test_a_user_can_create_a_project()
    {
        $this->withoutExceptionHandling();
        $attributes = [
            'title' => $this->faker->sentence,
            'description' => $this->faker->sentence,
        ];

        $this->post('/projects', $attributes)->assertRedirect('/projects');
        $this->assertDatabaseHas('projects',$attributes);
        $this->get('/projects')->assertSee($attributes['title']);
    }

 public function test_a_project_requires_a_title()
    {
        $this()->post('/projects', [])->assertSessionHasErrors('title');
    }

    public function test_a_project_requires_a_description()
    {
        $this()->post('/projects', [])->assertSessionHasErrors('description');
    }

my controller code

 public function store()
    {
        request()->validate([
            'title' => 'required',
            'description' => 'required'
        ]);
        Project::create(request(['title', 'description']));
        return redirect('/projects');
    }