I’m using last version of Home assistant OS version core-2021.12.4
I have acces from outside with duckdns using NGINX with no issues
Trying to integrate Smartthings
Searched all over for an answer
Very frustrated 
Popup window says:
SmartThings could not validate the webhook URL. Please ensure the webhook URL is reachable from the internet and try again
.
Home assistant logs says:
Logger: homeassistant.components.smartthings.config_flow
Source: components/smartthings/smartapp.py:145
Integration: SmartThings (documentation, issues)
First occurred: 10:37:25 AM (2 occurrences)
Last logged: 10:50:43 AM
API error setting up the SmartApp: {‘requestId’: ‘A581736-5B00-4FF5-BDC4-5667F0FA73E7’, ‘error’: {‘code’: ‘ConstraintViolationError’, ‘message’: ‘The request is malformed.’, ‘details’: [{‘code’: ‘TargetTimeoutError’, ‘target’: ‘https://mydns.duckdns.org/api/webhook/d04252fcaff57878e6a6bbc0ddbeaeb4eb365d2a02a7d609bdb6fd1f96651bc’, ‘message’: ‘Upstream target timed out’, ‘details’: }]}}
API error setting up the SmartApp: {‘requestId’: ‘D1EBBB1-CC86-475C-B564-8A016188C03D’, ‘error’: {‘code’: ‘ConstraintViolationError’, ‘message’: ‘The request is malformed.’, ‘details’: [{‘code’: ‘TargetTimeoutError’, ‘target’: ‘https://mydns.duckdns.org/api/webhook/d04252fcaff57878e6a6bbc0ddbeaeb4eb365d2a02a7d609bdb6fd1f96651bc’, ‘message’: ‘Upstream target timed out’, ‘details’: }]}}
Traceback (most recent call last):
File “/usr/src/homeassistant/homeassistant/components/smartthings/config_flow.py”, line 124, in async_step_pat
app, client = await create_app(self.hass, self.api)
File “/usr/src/homeassistant/homeassistant/components/smartthings/smartapp.py”, line 145, in create_app
app, client = await api.create_app(app)
File “/usr/local/lib/python3.9/site-packages/pysmartthings/smartthings.py”, line 110, in create_app
entity = await self._service.create_app(app.to_data())
File “/usr/local/lib/python3.9/site-packages/pysmartthings/api.py”, line 171, in create_app
return await self.post(API_APPS, data)
File “/usr/local/lib/python3.9/site-packages/pysmartthings/api.py”, line 395, in post
return await self.request(“post”, self._api_base + resource, data=data)
File “/usr/local/lib/python3.9/site-packages/pysmartthings/api.py”, line 368, in request
raise APIResponseError(
pysmartthings.errors.APIResponseError: Unprocessable Entity (422): {“requestId”: “A581763-5B00-4FF5-BDC4-5667FFA73E7”, “error”: {“code”: “ConstraintViolationError”, “message”: “The request is malformed.”, “details”: [{“code”: “TargetTimeoutError”, “target”: “https://mydns.duckdns.org/api/webhook/d04252fcaff55787e6a6bbc0ddbaeb4eb365d2a02a7d609bdb6fd1f96651bc”, “message”: “Upstream target timed out”, “details”: }]}}
Any ideas? Before I go nuts??