Run this at the command line to generate a new SSH Key-pair.

$>  ssh-keygen  -b 4096

Generating public/private rsa key pair.
Enter file in which to save the key (/Users/jminton/.ssh/id_rsa): ./gitlab-ssh                              
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
Your identification has been saved in ./gitlab-ssh.
Your public key has been saved in ./gitlab-ssh.pub.
The key fingerprint is:
SHA256:1C0I/F3DR53wsL05wgt1148tvS0jrSc7F/K03++bJe0 jminton@RKL-IMC-1RJ1-GT
The key's randomart image is:
+---[RSA 4096]----+
|     ..    . +o..|
|      .. o .+ *.o|
|       .o.o..= +o|
|       .. ..o .+=|
|        S  . oo++|
|            o.=o+|
|            .==++|
|            oo==+|
|            o* =E|
+----[SHA256]-----+
$>