I'm feeling nice, here's a tutorial for using private keys to authenticate using PuTTY. Your server provider should also have some documentation to show you how to connect
https://www.youtube.com/watch?v=2ZIaPFv2VhI
Find them here and go to their profile.
https://forum.plutonium.pw/users
Follow this
https://forum.plutonium.pw/topic/559/how-to-add-friends-on-plutonium