Where Can I Obtain the Code Expression for the Unique ID Without Copy-Pasting?

When the docs refer to expanding "Nodes > HTTP Request > Parameters > headerParameters > parameters > [Item: 0]" it means you need to use n8n’s Expression Editor to drill down into the output of your HTTP Request node to find the value you want to include in your message. The code (or expression) itself isn’t provided as a hard-coded snippet because it’s dynamically generated based on the data coming from your node’s execution.

Here’s how it works:

1. Access the Expression Editor:
   In the node where you want to use this value (for example, in a message or another node’s field), click on the gear icon or the “fx” button to open the Expression Editor.

2. Navigate to the Data:
   In the Expression Editor’s panel, you can browse the available output from all nodes. The reference “Nodes > HTTP Request > Parameters > headerParameters > parameters > [Item: 0]” tells you to expand the HTTP Request node’s returned data (often structured as JSON) until you reach the field that contains the Unique ID. Although you might not see a literal label saying “Nodes” in your UI, the interface organizes the data in a tree-like structure that matches this description.

3. Select the Value:
   Click on the desired field once you locate it. n8n will generate an expression (e.g. something like {{$json["headerParameters"]["parameters"][0]}}) that dynamically references that value. This way, the code is specific to your workflow’s data instead of a copy-paste snippet.

In short, the expression isn’t coming from a separate code repository or file—it’s built interactively using the Expression Editor based on the node output in your workflow. This allows you to adapt the reference to the actual data structure present after the HTTP Request node runs.

If you need further details on building expressions and accessing node output, you might want to check the documentation on Code in n8n and Expressions.