Logging in with a key is way safer (and easier) than using your password each time. Here is how to set it up on Ubuntu 18.
I assume you already have generated your SSH key.Â
$ ssh-keygen -t rsa 4096 -C "my key"
once you have the key just run
ssh-copy-id your-user-name@your-ubuntu-server-name
ssh-copy-id -i ~/.ssh/file.pub your-user-name@your-ubuntu-server-name
and you are all set! enjoy