API ip list

I have been working with this plugin and I am creating a very big website and going to move all my websites to use this plugin. At this moment I have this big site behind a firewall and took me like 3 days to understand why I was not receiving the comments, and the reason was the firewall that I had on digital ocean. is there any ip list that you have so I can include them in my firewall whitelist ?

Second question is if I can buy the product and use it in all the domains that I want, in the pricing page of your website is not detailed this.

Thanks in advance