Woocommerce bug fix

Our WooCommerce store is failing to send transactional SMS messages to customers after they place an order. We are using the HappyCoders SMS plugin integrated with MSG91. We received an official alert from MSG91 stating that our API calls are failing with Error Code: 400 (Bad Request).Required Skills:WordPress & WooCommerce developmentPHP & WooCommerce checkout hooks (woocommerce_thankyou)MSG91 API & Flow Builder integrationDLT template matching (India telecom regulations)Scope of Work:Fix the 400 Bad Request Error: According to MSG91 documentation, this error means the Template ID or Flow ID is missing, wrong, or archived. You need to log into our WordPress backend and MSG91 panel to map the correct, active Flow ID.Match Payload Variables: Verify that the dynamic shortcodes used by WooCommerce (like Customer Name, Order ID, Total) exactly match the variable placeholders inside our approved MSG91 DLT template.Verify API Endpoint: Ensure the HappyCoders plugin code is hitting the correct, updated MSG91 V5 Flows API endpoint, as older endpoints cause errors.Testing: Place a test order to confirm that the checkout completes smoothly and the transactional SMS is successfully delivered.Deliverables:Fully working post-purchase transactional SMS.Zero 400 errors in the MSG91 dashboard logs. Can you help ?