I solved this…
• Create an environment (Server-Admin), (no deployment targets needed)
• Create a Lifecycle (Server)
• Create a project for that lifecycle(server scripts).
• add a step of run script, selecting the “Run once on a worker” option. Since no workers are configured, octopus will chose the built-in worker.
chocolatey is installed, so the command “choco install -y aws-iam-authenticator” can be run.