sfp_api_laravel_ginastica_cerebro/app/Http/Resources/Select/GroupSelectResource.php

<?php

namespace App\Http\Resources\Select;

use Illuminate\Http\Request;
use Illuminate\Http\Resources\Json\JsonResource;

class GroupSelectResource extends JsonResource
{
    public function toArray(Request $request): array
    {
        return ['id' => $this->id, 'name' => $this->name, 'unit_ids' => $this->units->pluck('id')->values()];
    }
}