Create an SSH key

ssh-keygen.gist

ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/home/pi/.ssh/id_rsa): 
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /home/pi/.ssh/id_rsa.
Your public key has been saved in /home/pi/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:aXJj4P/GE24a1vSQbwXhISxZqRvD1RhFOqFXz85Y4Eg pi@pi-node1
The key's randomart image is:
+---[RSA 2048]----+
|         +EBB    |
|        oo=O.*   |
|      ...+= + +  |
|     . .=o o *   |
|      o S++ . +  |
|       *.+.+ .   |
|        +o..+    |
|       . o*.     |
|        .+..     |
+----[SHA256]-----+