I set up a entity in NodeRed called V5 with the following http request. (first http request is to set a pin to 1 followed by a delay and setting a pin back to 0
You could try replacing the V5 node with an Inject node, then you can use the inject node to kick off this flow, and see if the http request/delay/req nodes work as expected.
You can also add a debug node on the output of V5, and see when happens when you push it in HA