REST command issue

Dear All,

I am doing certain engneering automation for which I need to compute some integral values. For that I need to acces the historic data. The only way I found to make it from HA is through the REST commands. I have found that through the GET method I potentially can acces api/history/period records. But to do that I decided to get familar with the rest commands to start from, and that’s where I am stuck at the moment. I am trying to call from developer-tools/service my test command I defined in the config to understand if it works and nothing happends. Can anyone advise how to test these commands and where to look for the result?. Below is my zero approximation test command. It used to give me the error info in the log in previous notations, but now nothing happends - no error in the log, no result in the dev-tools… I am confused…

    url: http://localhost:8123/api/
    method: GET
      authorization: !secret rest_api_token
      content-type: 'application/json'