AFAIK only Homey (cloud/premium) can handle http POST requests (tested). And it’s not local. Homey Pro’s don’t seem to able to process POST data by the “web event received” logic card. You’ll have to request for POST support at Athom https://homey.app/support
Or, maybe Thomas can add POST data functionality to the local webtrigger function of his neat Micro Web Server app, you can ask him if it’s possible, and if he’s interested to build it, in this thread here:
I tested to be sure, but it solely works with GET data atm.