ONTASKDELETE

<!-- Load the SDK (UMD build); it is exposed as the global B24Js -->
<script src="https://unpkg.com/@bitrix24/b24jssdk@1/dist/umd/index.min.js"></script>
<script>
  async function bindTaskDeleteEvent() {
    try {
      // Initialize the SDK inside a Bitrix24 frame
      const $b24 = await B24Js.initializeB24Frame()

      const response = await $b24.actions.v2.call.make({
        method: 'event.bind',
        params: {
          event: 'onTaskDelete',
          handler: 'https://example.com/handler.php',
        },
        requestId: B24Js.Text.getUuidRfc4122()
      })

      // The payload is available only on a successful response
      if (!response.isSuccess) {
        console.error(response.getErrorMessages().join('; '))
        return
      }

      const result = response.getData().result
      console.info('Event bound successfully:', result)
    } catch (error) {
      // Thrown on transport or SDK failures (AjaxError, SdkError, etc.)
      console.error(error)
    }
  }

  document.addEventListener('DOMContentLoaded', bindTaskDeleteEvent)
</script>

from b24pysdk.errors import BitrixAPIError, BitrixSDKException

try:
    bitrix_response = client.event.bind(
        event='onTaskDelete',
        handler="https://example.com/handler.php",
    ).response
    result = bitrix_response.result
    print(result)
except BitrixAPIError as error:
    print(
        "Ошибка Bitrix API",
        f"error: {error.error}",
        f"error_description: {error.error_description}",
        sep="\n",
    )
except BitrixSDKException as error:
    print(f"Ошибка Bitrix SDK: {error.message}")
except Exception as error:
    print(f"Непредвиденная ошибка: {error}")

try {
    $response = $b24Service
        ->core
        ->call(
            'event.bind',
            [
                'event'   => 'onTaskDelete',
                'handler' => 'https://example.com/handler.php',
            ]
        );

    $result = $response
        ->getResponseData()
        ->getResult();

    echo 'Success: ' . print_r($result, true);
    // Нужная вам логика обработки данных
    processData($result);

} catch (Throwable $e) {
    error_log($e->getMessage());
    echo 'Error binding event: ' . $e->getMessage();
}

BX24.callMethod(
    'event.bind',
    {
        "event": "onTaskDelete",
        "handler": "https://example.com/handler.php"
    },
    function(result) {
        if (result.error()) {
            console.error(result.error());
        } else {
            console.info(result.data());
        }
    }
);

require_once('crest.php');

$result = CRest::call(
    'event.bind',
    [
        'event' => 'onTaskDelete',
        'handler' => 'https://example.com/handler.php'
    ]
);

echo '<PRE>';
print_r($result);
echo '</PRE>';