59103: Resource Already Exists

A Rule with the same match key (the combination of matchType and value, such as the same URL prefix) already exists for this account.

• A POST /v1/Webhooks/Rules request was made with a matchType/value pair that duplicates an existing Rule.

• List existing Rules (GET /v1/Webhooks/Rules) to find the conflicting rule.
• If you intend to change where that pattern routes, PATCH the existing Rule's settings instead of creating a new one.
• If you intend to replace it, delete the existing Rule first, then create the new one.