1. simply ssh-keygen into terminal
ssh-keygen
2. go into C:\Users\<user>.ssh and cat id_rsa.pub
cd %HOMEPATH%\.ssh
cat id_rsa.pub
or
cat %HOMEPATH%\.ssh\id_rsa.pub
3. copy everything (yes ssh-rsa and computer aswell)
4. ssh into your target server and place the string into ~/.ssh /authorized_keys
nano ~/.ssh/authorized_keys
5. Voilà, everything should work as intended.
Try with ssh <user>@<ip>