How to execute the Apex REST API from the REST CLient?

Question

I am new to the SalesForce and trying to execute the below from the workbench the same I want to execute from the Mozilla REST client. What URL I should be using?

So What should I be used here ?

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As per guidance from Dan, I am getting the required output:

Answer 1

I believe from an outside system you will need to first get an auth token and then use that to call the service you are using. So below I have listed the steps you would need to use to get what you see.

Create a new Connected App

From the Connected App get he Consumer Key and Consumer Secret

User the following format to get your auth token in POST request (User test or login based on sandbox or developer/production org:

https://"Login or test".salesforce.com/services/oauth2/token?client_id="Consumer-Key"&client_secret="Consumer-Secret"&username="UserName"&password="Password-SecurityToken"&grant_type=password

Get access_token from below response

{
      "access_token": "AccessTokenHere",
      "instance_url": "URL",
      "id": "Id",
      "token_type": "Type",
      "issued_at": "Issued",
      "signature": "Signature"
    }

Send GET request with new access token as header in following format: Authorization: Bearer access-token

I hope this helps.