IP address whitelisting

Hello,

I have an e-commerce website and we have a supplier who supplies us with there digital products. However, in order to full integrate with the suppliers api, we are trying to add the IP address for the website moesgiftcards.com to their whitelist. after doing a whois lookup we had 3. Are there any other IP addresses that we should add to the whitelist in order successfully integrate with our suppliers api? We have added all the public ip addresses that show up but we still get the error that the ip is not in the whitelist.

Thank you

If this is an outbound whitelist for them to connect to your site, then those three IP addresses should be good for the foreseeable future.