Send mail notifications to multiple addresses failed

[zrkb]

According to #743, it is possible to send mail notifications to multiple addresses setting an array instead of a string, but I've tested it and it fails miserably.

Digging through the code I found the culprit was the return type declaration for routeNotificationForMail() method in the Notifiable class that only return strings.

laravel-backup/src/Notifications/Notifiable.php

Line 11 in f15a677

public function routeNotificationForMail(): string

I've resolved this by making a copy of that class, removing the return type declaration, and replacing it on backup.php config but it will be cool if this works out the box.

[freekmurze]

This has been fixed in the latest release.

[vrusua]

Still getting the same issue for multiple addresses when trying setting them as an array instead of a string.

To reproduce you can run:
php artisan vendor:publish --tag=laravel-assets --ansi --force

Spatie\Backup\Exceptions\InvalidConfig::invalidEmail(): Argument #1 ($email) must be of type string, array given, called in /app/vendor/spatie/laravel-backup/src/Config/NotificationMailConfig.php on line 23

v.9.0