You’ll need to first install Nix:

curl -L | sh

Then exit your terminal and start it again, so that the Nix environment loads.

Next you need to install Cachix:

nix-env -iA cachix -f

Then with the previously generated token:

CACHIX_AGENT_TOKEN=... cachix deploy agent myagent

You should see an agent appear at your workspace.

Continue by making your first deployment for your agent.