本筆記參考:
1. https://panjeh.medium.com/laravel-cloudflare-logging-real-visitor-ip-address-server-solution-1e9739e89654
2. https://laracasts.com/discuss/channels/laravel/cloudflare-and-user-ip
3. https://qiita.com/ziming/items/575355bdf383b1ec4d92
4. https://stackoverflow.com/questions/60777969/request-ip-in-laravel-application-not-correct
5. https://khalilst.medium.com/get-real-client-ip-behind-cloudflare-in-laravel-189cb89059ff
6. https://thisinterestsme.com/php-ip-address-cloudflare/