i put in an ip and it just says an error message.

make sure your friend has a server open and given you the right number

It depends on if you have port forwarded. (Important keywords in bold.) Port forwarding is the process of opening ports on your router to allow connections from other computers. Usually, you can just google "Port forward (Your router name)" and find out how. Make sure its port forwarding, not port triggering or DMZ (unless you want less security.) Next, you will need your ipv4. You can go to ipchicken for this. Next, send your friend your ip and port that you opened for NOVETUS. If you are joining your friend, make sure they have port forwarded. If they have not, upnp may work. If not, then teach them the steps on how to port forward using this guide, and your should be able to join them! Also, make sure your NOVETUS is up to date. If it is not, then update, or make sure your friend updates to your current version!

That is all, I am heree.

can someone make a video about it

i dont know if this counts but im hosting on my own pc and trying to join on my own pc is this possible currently im putting localhost:9683 but ive tryed localhost and it still didn't work i put in the port still didn't work is it possible to host and join on the same pc or is it impossible