SATE-EasyReceipt/app/Mail/TextMail.php

<?php

namespace App\Mail;

use Illuminate\Bus\Queueable;
use Illuminate\Queue\SerializesModels;

class TextMail extends BaseMailer
{
    use Queueable, SerializesModels;

    private string $__subject;
    private string $__contents;

    public function __construct(string $subject, string $contents)
    {
        $this->__subject = $subject;
        $this->__contents = $contents;
    }

    public function getTemplateName(): string
    {
        return 'mails.free_text';
    }

    public function getSubject(): string
    {
        return $this->__subject;
    }

    public function getParams(): array
    {
        return [
            'contents' => $this->__contents,
        ];
    }
}