Certificates can have multiple usages and you didn’t specify the purpose in your case. A certificate is not necessarily tied to an IP or even a server. However, if you want to authenticate the server with a certificate, you will need the IP address to be resolved by a DNS. So, you should clarify what you actually want to accomplish. Do you expect your certificates to be self-signed or signed by a certification authority? A certification authority cannot validate a private IP address.
Certificates can have multiple usages and you didn’t specify the purpose in your case. A certificate is not necessarily tied to an IP or even a server. However, if you want to authenticate the server with a certificate, you will need the IP address to be resolved by a DNS. So, you should clarify what you actually want to accomplish. Do you expect your certificates to be self-signed or signed by a certification authority? A certification authority cannot validate a private IP address.