Help: Trigger a flow from a SKY Add-in button

Hi folks, I keep getting this error message when clicking the button created in NXT to connect to a PowerAutomate flow: "The web request action returned an error response: 401"

I'm following the instructions for invoking the flow here: Invoke a flow - Microsoft Integrations

and the instructions for the Web Request Action SPA here: Invoke a web request - SKY API

I started with the template flow named "Trigger a flow from a SKY Add-in button" as suggested by the instructions in the first link.

I've confirmed that the application id of my app ("41fc5b2f-417d-4297-887b-734574c45185" is entered correctly in the "Validate User Identity token" action of my flow:

I've used the URL generated by the trigger step ("https://edcbce3fd967ed739cac6f14687056.1c.environment.api.powerplatform.com:443/powerautomate/automations/direct/workflows/6247cda82b094096ab1d110959bf86dd/triggers/manual/paths/invoke?api-version=1)

along with the instructions from the second link to create the web request action URL for the add-in:

I believe all my permissions are up-to-date.

Does anything look wrong or did I miss a step?

Appreciate any thoughts or suggestions you might have. Thanks!!