Hi @FoDelement
I think there are some crossed wires here, I am not suggesting you set up an IFTTT account.
IFTTT is a platform not too unlike Flow.
The user in the video triggers his process by sending an HTTP request, as you would do in Flow.
The "When an HTTP request is recieved" trigger in Flow works as long as you send an HTTP request to it, from somewhere. In whichever means you choose to send that HTTP request to Flow is up to you.
The video in the link shows the presenter sending an HTTP request with PowerShell, triggered by running a batch file. I see it working in Streamdeck so shared it with you to get you off and runnig conceptually.
To trigger the Flow, you send the HTTP request to the URL provided by the connector.

If you have found my post helpful, please mark thumbs up.
Any other questions, just ask.
Thanks, Alan