provisioning – How to pass current user email to Power Automate using site script

I want to trigger Power Automate through site design (inside site script). Found documentation from MS on how to implement this. There is a way to trigger flow using triggerFlow verb and with When Http Request is Received action. But I want to pass currently logged in user email address or user id or at least a display name to my flow as parameter. What is the way to pass? Reason behind this is, I need to send email notification through flow who applied that particular site design. Below is sample format

{
    "$schema": "schema.json",
    "actions": (
    {
            "verb": "triggerFlow",
            "url": "(paste the workflow trigger URL here)",
            "name": "Apply Template",
            "parameters": {
                "userId":"????????????????????????????",
                "userEmail":"?????????????????????????"
            }
    }
    ),
    "bindata": {},
    "version": 1
}