keksAccount/app/Http/Resources/API/Mail.php

<?php

namespace App\Http\Resources\API;

use Illuminate\Http\Resources\Json\JsonResource;

class Mail extends JsonResource
{
    /**
     * Transform the resource into an array.
     *
     * @param  \Illuminate\Http\Request  $request
     * @return array
     */
    public function toArray($request)
    {
        return [
            'id' => (int)$this->id,
            'created_at' => $this->created_at,
            'updated_at' => $this->created_at,
            'status' => $this->status,
            'primary' => (boolean)$this->primary,
            'mail' => $this->mail
        ];
    }
}