35132: Bulk : Provided Attributes JSON is not valid

Twilio returns this error when a bulk messaging request includes Attributes that are not valid JSON.

• The Attributes value is not valid JSON.
• The attribute payload is malformed or does not match the expected format. This is an inference based on the error text.

• Update the Attributes value so it is valid JSON before you resend the request.
• Check each attribute for the expected format and correct any malformed fields.

• Messaging API overview
• Messages resource