autocde2.0/tests/Feature/API/PlanTest.php

<?php

namespace Tests\Feature\API;

use App\Models\Plan;
use Tests\Feature\TestCase;


class PlanTest extends TestCase
{
    public function test_create_plan(): void
    {
        $form = Plan::factory()->make();

        $response = $this->post(route('plan.store'), $form->toArray());

        $response->assertStatus(201);
    }
}