It's a dedicated server and we have WHM to manage it. So could it be possible that the server has an IP XYZ for now. After an hour, we need the server to change its IP to something else and so on.
So, I hope it makes sense, how to achieve it?
A LAMP server usually only cares about it's hostname, since you probably don't want to host a site on an IP address only. So from the server point of view usually you don't have to change anything.
About changing your IP: The IP is nothing that the server can set itself. The IP is assigned to the server by the ISP and that depends on where your server is hosted. If it's a self-hosted server you usually get a fixed IP assigned which you cannot change. You might be able to change it by asing the support guys of your hoster, but they will pretty sure not change it every hour.
You could achieve something like this - if you would really need to - for example if you host your server in the cloud. AWS (Amazon Web Services) for example has something which is called "Elastic IP". That's a pool of IP addresses you can assign to your servers yourself.
The basic question is: What do you want to achieve with it? Because usually that's not something that someone would need at all.