IP Whitelisting to allow only limited Users

I just read the documentation and I still do not understand. I am attempting to block all users except for the IPs in a whitelist so no one except my permission can enter into the network. How do I accomplish this using vpn?

I tried changing DNS by PureVPN DNS, but it didn't helped me much. I've created a seperate whitelist file local and added and as whitelisting, but no help. It doesn't make sense that sometimes the VPN works but sometimes it doesn't.

I tried following these guides but still not sure
www.hostgator.com/help/article/how-to-wh...ip-windows-dedicated
www.malcare.com/blog/how-to-whitelist-an-ip-address/