ssh-keygen not found

Symptom

Get-Command ssh-keygen returns nothing.

Resolution

Windows

Install OpenSSH via "Settings" → "Apps" → "Optional features" → "Add a feature" → "OpenSSH Client".

Verify:

Get-Command ssh-keygen

macOS

OpenSSH is shipped with the OS. If ssh-keygen is missing, install via Homebrew:

brew install openssh

Linux

Install via the system package manager:

sudo apt install openssh-client   # Debian / Ubuntu
sudo dnf install openssh-clients  # Fedora / RHEL

Verify:

which ssh-keygen