Health › checks. Pick Process running. The agent counts processes by name. You are still pushing a document, not a script.
Open the machine, then health › checks. The primitive is Process running. Name is the process. Min instances is how many copies must be there; 1 is the usual case. On Accounts server that is sqlservr. Check that a service is running is the service, which is a different thing from the process. Add a disk or ping check is the same editor.
Press add to list. The check sits in the document. Push to agent is the next click, and it asks you to confirm. Push replaces the whole document. This shot stops before that, so nothing has been sent. When the process is missing, the alert is a check failure. It resolves when the process is back.
Push is a two-step button. The agent must be online to evaluate. You can still add the check while it is offline, and it applies at the next hello. A service is Check that a service is running. Free space and a ping are the same editor.