Subscribing to a webhook for Google channel doesn't work from the UI

[ljupcovangelski]

When subscribing to a webhook for the Google channel, from the Google Business Dashboard, it returns an error: URL returned an unknown error.

When subscribing form the Google Business API - everything works as expected with the following call:

curl -X PATCH \
"https://businesscommunications.googleapis.com/v1/partners/ORGANIZATION_ID?updateMask=productCapabilities" \
-H "Content-Type: application/json" \
-H "User-Agent: curl/business-communications" \
-H "$(oauth2l header --json ./SERVICE_ACCOUNT_AUTH_FILE businesscommunications)" \
-d "{ \
  'productCapabilities': [ \
    { \
      'product': 'BUSINESS_MESSAGES', \
      'businessMessagesCapability': {
        'webhookUrl': 'https://PUBLIC_AIRY_FQDN/google',
      },
    },
  ],
}"

Screenshot in attachment (the URL and the token are irrelevant):

[steffh]

@ljupcovangelski: This is not a publicly available tool and API, so the issue here might be actually related to webhook verification requests in general?

Could it be the case that our general behavior for incoming requests at the relevant POST /google route is to verify the webhook using the partnerKey?

For the verification requests triggered from this internal UI, the relevant behavior might be different as compared to PATCH updates to existing webhooks via the API because the partnerKey verification might fail in that case?