KT-MyPage/app/Email/Members/Members.php

<?php

namespace App\Email\Members;

use App\Email\BaseEmailer;
use App\Kintone\Models\Customer;

abstract class Members extends BaseEmailer
{

    public function __construct(protected Customer $customer)
    {
        $this->setEmail($customer->email);
    }

    public function getParams(): array
    {
        return array_merge($this->getMemberParams(), [
            'customer_name' => $this->customer->customerName
        ]);
    }

    abstract public function getMemberParams(): array;
}