Does that means the port to open is now 443 instead of 5228?
To receive messages
You should open 5228, 5229 and 5230 as per the documentation.
To send messages
FCM doesn’t provide specific IPs because our IP range changes too frequently and your firewall rules could get out of date impacting your users’ experience.
Ideally, you will whitelist ports 5228-5230 with no IP restrictions.
However, if you must have an IP restriction, you should whitelist all of the IP addresses in the IPv4 and IPv6 blocks listed in Google’s ASN of 15169. This is a large list and you should plan to update your rules monthly.