All webhook requests from the Bot API are now coming from the subnets 149.154.160.0/20 and 91.108.4.0/22. Most users won't need to do anything to continue receiving webhooks. If you control inbound access with a firewall, you may need to update your configuration. You can always find the list of actual IP addresses of servers used to send webhooks there: https://core.telegram.org/bots/webhooks