autocde2.0/app/Http/Requests/API/Requirement/LinkPlanRequest.php

<?php

namespace App\Http\Requests\API\Requirement;

use Illuminate\Foundation\Http\FormRequest;

class LinkPlanRequest extends FormRequest
{
    /**
     * Determine if the user is authorized to make this request.
     */
    public function authorize(): bool
    {
        return true;
    }

    /**
     * Get the validation rules that apply to the request.
     *
     * @return array<string, \Illuminate\Contracts\Validation\ValidationRule|array<mixed>|string>
     */
    public function rules(): array
    {
        return [
            'requirement_ids' => [
                'required',
                'array',
            ]
        ];
    }
}