laravel smtp setup showing error

laravel-smtp-issue-fix.php

'smtp' => [
            'transport' => 'smtp',
            'host' => env('MAIL_HOST', 'smtp.mailgun.org'),
            'port' => env('MAIL_PORT', 587),
            'encryption' => env('MAIL_ENCRYPTION', 'tls'),
            'username' => env('MAIL_USERNAME'),
            'password' => env('MAIL_PASSWORD'),
            'timeout' => null,
            'stream' => [
                'ssl' => [
                    'verify_peer' => false,
                    'verify_peer_name' => false,
                    'allow_self_signed' => true,
                ],
            ],
        ],

laravel 9 and above

'smtp' => [
            'transport' => 'smtp',
            'host' => env('MAIL_HOST', 'smtp.mailgun.org'),
            'port' => env('MAIL_PORT', 587),
            'encryption' => env('MAIL_ENCRYPTION', 'tls'),
            'username' => env('MAIL_USERNAME'),
            'password' => env('MAIL_PASSWORD'),
            'timeout' => null,
            'verify_peer' => false,
                    'verify_peer_name' => false,
                    'allow_self_signed' => true,
        ],