Hi,
All Instance level public IP addresses are charged depending on what type of IP address you use:
More information here:
Public IP Address pricing
https://azure.microsoft.com/en-us/pricing/details/ip-addresses
You can use the REST API below to list all public IP addresses:
https://learn.microsoft.com/en-us/rest/api/virtualnetwork/publicipaddresses/listall
Or you can use Azure CLI to scan all public IPs:
Scan all public IP in Microsoft Azure using Azure CLI and Nmap
Best regards,
Leon