Private network in Centos 8 issue

Centos 8 has cloud-init, and we want to setup private ip for this server for internal connectivity between server. I tried to setup "ifcfg-eth1" config file with all details and rebooted server. But its not working. We have a infrastructure setup at ovh. Our problem is that we are not able to assign private ip to the new server we just set up so we want help to get this server added to network.