Set IP policies
You can set IP policies for each port in the ports & DNS page of a service. Find the port you want to set IP policies for and open the security rules or custom domains & security rules section.
You can enter specific IP addresses to allow or deny access to your service's ports, or enter CIDR blocks to allow or deny ranges of IP addresses. For example,
192.168.0.0/24 would block or allow IP addresses in the range
Allowing an IP address, or a range of addresses, will block all other IP addresses.
Denying an IP address will always take precedence over allowing an IP address, so it isn't possible to deny a range of IP addresses and allow specific ones within that range. You can, however, allow a range of IP addresses and deny specific IP addresses within the range.