Press New playbook, give it a name, and pick the rule it runs for under "When this rule fires".
Pick which machines it runs on. It is never wider than the rule's own machines.
Add steps in order, up to the limit shown: restart a service, restart a container or run one command. A template can give you a start.
Press Preview to see what would run, on which machine, without running anything. The answer appears right under the button, and says so plainly when there is nothing to preview or it cannot be worked out.
Pick a mode. "Ask me every time" asks before each run. "Run by itself" needs your name under Approve as, and Approve and save.
Something not working?
A playbook ran nothing: the app must be open, and each machine's own ceiling must allow the step.
A step waits for approval: approve it from the approval sheet. It goes through the same checks as anything else.
Saving a change clears the approval of an automatic playbook: preview and approve it again.
Runs on this page shows what ran and the result of each step.