Challenge 1: Convert a Postman Request to .http — Possible Solution
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POST {{baseUrl}}/orders
Authorization: Bearer {{authToken}}
Content-Type: application/json

{
  "productId": "P200",
  "quantity": 1
}

WHY THIS WORKS AS AN ANSWER
------------------------------
The method and URL go on the first line, exactly as in Postman's
method-dropdown-plus-URL-bar, just written as one line of text instead
of two separate UI fields.

Both headers (Authorization and Content-Type) go directly below that
first line, one per line, with no blank line between them — headers
are grouped together as a block.

The REQUIRED blank line comes after the last header and before the
body — this is the exact separator the REST Client extension uses to
know where headers end and the body begins; without it, the JSON body
would be misread as more header lines.

The JSON body follows exactly as it would appear in Postman's raw JSON
body editor — no special escaping or extra syntax needed beyond valid
JSON itself.

{{baseUrl}} and {{authToken}} both reference variables the same way
Postman's {{variable}} syntax does — defined either with @name = value
at the top of the file, or supplied via an http-client.env.json
environment file per this chapter's variables section.