Login to new server as root, then add a deploy user
sudo useradd --create-home -s /bin/bash deployer
sudo passwd deployer
First line add a new user named deploy, create a home directory for it (/home/deployer), and give it a login shell (/bin/bash).
sudo useradd --create-home -s /bin/bash deployer
sudo passwd deployer
Make directory .ssh on the remote server and log out
mkdir /home/deployer/.ssh
touch /home/deployer/.ssh/authorized_keys
Push your ssh key to the authorized_keys file on the remote server
scp ~/.ssh/id_rsa.pub [email protected]:~/.ssh/authorized_keys
Then chown and chmod it to lock it down:
chown -R deployer. /home/deployer
chmod 600 /home/deployer/.ssh/authorized_keys