Saving timeseries values into a number helper?

I have a timeseries of values:

{ “value”: 30, “timestamp”: “2023-10-09T07:30:00” }
{ “value”: 33, “timestamp”: “2023-10-09T08:00:00” }
{ “value”: 37, “timestamp”: “2023-10-09T08:30:00” }
{ “value”: 31, “timestamp”: “2023-10-09T09:00:00” }

I was hoping to store the half hourly energy prices collected in node red and store into a number helper so that I can show a graph on the values in Home Assistant.

I have not had much luck with making http calls the the ha API, and using a call service node does not allow the timestamp to be set.

Does anybody have suggestions as to how best to store this information in home assistant?