40157: Dequeue Instruction does not have a valid 'status_callback_url' parameter

This error occurs when your Assignment Callback response includes a dequeue instruction with a status_callback_url value that TaskRouter cannot use. In a dequeue instruction, status_callback_url is optional, but if you provide it, it must be a well-formed http:// or https:// URL string that TaskRouter can use for asynchronous webhook GET requests about the worker call.

• You provided status_callback_url as an empty string.
• You provided status_callback_url with the wrong data type instead of a URL string.
• The status_callback_url value is not a well-formed http:// or https:// URL.
• Your application generated a dequeue instruction payload where status_callback_url was serialized incorrectly, so TaskRouter did not receive a valid URL string.

• Set status_callback_url to a complete http:// or https:// URL string.
• Remove status_callback_url from the dequeue instruction if you do not need asynchronous worker call status webhooks.
• Verify that your Assignment Callback returns valid JSON for the dequeue instruction and that status_callback_url is serialized as a string.
• If you also send status_callback_events, provide a valid status_callback_url so TaskRouter has a destination for those event webhooks.

• Handling Assignment Callbacks
• Queueing Twilio calls with TaskRouter
• Webhooks (HTTP callbacks): Connection Overrides