How to add HTTP headers to call external API ?

[abhi34]

I have been trying to call an external API(Zendesk API) from the SN personal instance Previously , i would use the following code in my server side script(on NodeJS) and it would work perfectly fine . 

app.get("/api/v2/tickets/:TICKET_ID/comments.json", function(req, res) {
    debugger;
    var options = {
      method: "GET",

      url:
        process.env.ZENDESK_HOST +
        "/api/v2/tickets/" +
        req.params.TICKET_ID +
        "/comments.json",
      headers: {
        authorization: process.env.ZENDESK_TOKEN
      }
    };

    request(options, function(error, response, body) {
    //Somecode
  });

Now i am trying to do the same in ServiceNow.  The problem i am facing is how do i  add the headers(which can be seen above ) in ServiceNow HTTP request . 
My approach in (ServiceNow) has been to create a new REST Message(call it test2 )  : 

1.)Fill in the endpoint 

2.) Selected ->AUTHENTICATION TAB ->Add authorisation(tried both basic and NO authorization ) . While trying basic  created a new "Basic Auth Configurations" and added some random username and password. 

3)Selected ->HTTP REQUEST -> Tried adding Headers , but the add(+) button wont work . 

See below : 

4.)Anyhow submitted the REST Message and Selected "Test" ,and then  i see this  : 
4a.)HTTP Status : 401 

4b.) Error Message :  Invalid username/password combo

4c.)Response : {"error":"Couldn't authenticate you"}

After this i returned to STEP 3 to add headers , just in case . But it is still unclickable . 
I tried reading through the documents to call API in SN , and tried many approaches but none seem to work for me . 

Any help will be greatly appreciated . 

[DScroggins · Accepted solution]

Hello. You can double click on the message 'Insert a new row...' under the name column to add the header. Then double click on the white space under the value column to add the header value. Hope this helps.

[abhi34]

Thanks a lot !!! 
I tried doing something similar to what you just said . What i tried was double click on 
Insert a new row" but this does not work . First the value has to be added . 

You saved a lot of time of mine. 🙂