Expose your localhost if you are running your server behind NAT.

gistfile1.txt

What you will need: Server behind NAT (Server A), Server with static ip e.g. VPS for hosting Wireguard (Server B).

1) On your server B paste this commands in terminal: curl -O https://raw.githubusercontent.com/angristan/wireguard-install/master/wireguard-install.sh && chmod +x wireguard-install.sh && ./wireguard-install.sh
2) Create new client and save his ip. Mine will be 10.66.66.123 
3) Download this config to server A and connect to your server B with wireguard.
4) Depending on your client ip which we configured in step 2 type this commands in server B terminal (this time I wanted my Minecraft server exposed, so I chose 25565 port, yours can depends):

sudo iptables -P FORWARD DROP
sudo iptables -A FORWARD -i wg0 -o eth0 -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT
sudo iptables -A FORWARD -i eth0 -o wg0 -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT
sudo iptables -A FORWARD -i eth0 -o wg0 -p tcp --syn --dport 25565 -m conntrack --ctstate NEW -j ACCEPT
sudo iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 25565 -j DNAT --to-destination 10.66.66.123

5) While you are connected to server B through the Wireguard, your Minecraft server proxied and can be accessible through your server B external ip. Good luck :-)