Hi, you can use a domain name for your members to use when direct connecting. From my experience there is no actually way to hide your IP even with a domain the domain only helps a tiny bit. If you would like a secure server i recommend getting a DDOS Protected VPS Many VPS Hosts offer them on their website. The link below is how to set up a domain name for you server if you are interested.
Stay Safe And Have A Great Day/Night.
Best Regards Tom