How to utilize trigger output in a raw body request within a webhook

I'm having issues accessing the output from a start trigger and using it within a raw body request of a webhook. Below is what I tried as my raw body request, but when I run the workflow, the input simply shows the variable reference and not the actual value. How are outputs from nodes accessed/used in following nodes?

    "filters": [
    "fields": [

Trigger workflows with webhooks

Hello and welcome to the forums!

Can you show a bit more of the detail of your workflow setup with a screenshot or two? When you say that you are having issues with the startTrigger output and

do you mean that you are triggering a secondary workflow with the data?

Generally, nodes in workflows are linked via these output connections:

and then referenced within the next blocks: