Use Custom HTTP Webhook when your SMS provider accepts a compatible HTTP request. Configure the request from that provider’s API documentation; the gateway does not automatically translate every provider’s authentication or payload format.

Prepare the request details

Obtain the provider’s HTTPS send URL, required request method, authentication headers, body format and documented success response. Confirm the sender and destination are usable for that account. The outbound gateway sends to your provider; it is separate from an API that lets another system send through your WHMCS installation.

Add the gateway

1. Open PD Modules → SMS Manager → Gateways → Add a gateway.
2. Choose Custom HTTP Webhook and enter a recognisable gateway name.
3. Set HTTP method to the provider’s supported GET or POST method and fill Request URL.
4. For POST, choose Body format and enter Request body (POST). GET does not use that body.
5. Enter any provider-required Extra headers, one header per line.
6. Review From (optional) and Success contains (optional), then save.

Match the placeholders to the provider

Request URL and body templates can use {to}, {to_digits}, {message} and {from}. The first phone form includes its international plus; the digits form omits it. URL placeholders are encoded. Form and JSON body formats apply their corresponding escaping, while Raw sends the substituted body as-is.

Use the provider’s actual parameter names. For example, to={to}&message={message} is useful only if its form API expects those names. JSON string values need the appropriate surrounding quotation marks. Extra headers are configured values, not a second message-placeholder template.

Verify deliberately

Test connection checks the configured URL locally; it does not call the endpoint or prove that the credentials work. Log only tests module processing without exercising this HTTP request. An intended Send test SMS is a separate, potentially chargeable action. Inspect History and the provider result, and reconcile an Unknown timeout before repeating it.

See the PD SMS Manager WHMCS guide for related tasks, or explore PD SMS Manager.