One suggested way to install ssh encryption for this addon
Generate a key
Open a terminal in HA using one of the terminal addons, the Code Server (VSCode) addon, or from the front end of HA pi, etc. Note Home Assistant OS and Supervised mode use the folder /ssl to store the encryption files in. This replaces the ~/.ssh folder many Linux distro's use.
At the terminal prompt:
ssh-keygen -f ~/ssl/something-unique-ed25519 -t ed25519