Update api-proxy.mdx

Author: dannyroosevelt

docs-v2/pages/connect/api-proxy.mdx

@@ -100,7 +100,6 @@ const resp = await pd.makeProxyRequest(
     options: {
       method: "POST",
       headers: { // These get sent to the downstream API
-        authorization: "Bearer {{oauth_access_token}}", // Include the special {{ oauth_access_token }} macro
         hello: "world!"
       },
       body: {
@@ -136,9 +135,15 @@ You can also send a request to the Connect REST API with the below config:
 
 - If using the REST API, include the `Authorization` header with your Pipedream OAuth access token (`Bearer {access_token}`)
 - Headers that contain the prefix `x-pd-proxy` will get forwarded to the downstream API
+- If the downstream API requires [custom authorization headers](#authenticating-on-behalf-of-a-user), make sure to prepend with `x-pd-proxy` and include the macro `{{ }}` that Pipedream will replace with the actual value. For example,
+
+```javascript
+"x-pd-proxy-apiKey: {{api_key}}"
+```
 
 ```bash
-# First, obtain an OAuth access token
+# First, obtain an OAuth access token to authenticate to the Pipedream API
+
 curl -X POST https://api.pipedream.com/v1/oauth/token \
   -H "Content-Type: application/json" \
   -d '{