Power Platform Community Forum Thread Details

Hi everyone,

I’m trying to retrieve the callback URL of a Power Automate flow that uses the “When an HTTP request is received” trigger.
My objective is to automate/postman-test the flow by dynamically acquiring the HTTP trigger URL instead of manually copying it.
However, every documented approach so far has failed. Below is a detailed summary of everything I tried.
What I have already done

My user account is a System Administrator in the environment.
I also assigned myself the Environment Maker role.
I generated a fresh OAuth token after receiving Maker permissions.
I used the correct environment ID, not just the display name.
Verified that the flow exists in that environment.
Tried with both user tokens & app registrations.

What didn’t work
https://api.flow.microsoft.com/providers/Microsoft.ProcessSimple/environments/{envId}/flows/{flowId}/triggers/When_a_HTTP_request_is_received/listCallbackUrl?api-version=2016-11-01

Headers included:

Authorization: Bearer <token>
Content-Type: application/json
x-ms-client-scope: /providers/Microsoft.ProcessSimple/environments/{envId}

Even though I am a System Admin + Environment Maker.
Still got:
{
    "error": {
        "code": "ClientScopeAuthorizationFailed",
        "message": "The x-ms-client-scope header must not be null or empty."
    }
}

Even when the header was present.
My goal is simply to programmatically obtain the HTTP POST URL of an HTTP trigger flow so that I can call it from Postman or external systems like scripting without manually copying it.
Any official guidance, documentation, or workaround would be greatly appreciated.

Thanks!

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