Example

final displaySettings = PaymentOptionsDisplaySettings(
  mode: state.paymentOptionsDisplayMode ?? PaymentOptionsDisplayMode.BOTTOM_SHEET,
  visibleItemsCount: paymentsListItemCount,
  defaultSelectedPgCode: state.defaultSelectedPayment,
);

final args = CheckoutArguments(
  merchantId: state.merchantId,
  apiKey: state.apiKey,
  sessionId: state.sessionId ?? "",
  amount: amount,
  showPaymentDetails: state.showPaymentDetails,
  paymentOptionsDisplaySettings: displaySettings,
  setupPreload: state.preloadPayload == true ? _apiTransactionDetails : null,
  formsOfPayment: formOfPayments?.isNotEmpty == true ? formOfPayments : null,
  theme: _theme,
);

//
Scaffold(
  appBar: AppBar(
    backgroundColor: Theme.of(context).colorScheme.inversePrimary,
    title: Text(widget.title),
  ),
  body: SingleChildScrollView(
    child: Column(crossAxisAlignment: CrossAxisAlignment.stretch, children: [
      SizedBox(height: 46),
      Text(
        "Customer Application",
        textAlign: TextAlign.center,
        style: ts.TextStyle(fontSize: 24),
      ),
      //Start of Merchant content
      const Padding(
          padding: EdgeInsets.all(12.0),
          child: Text(
            "Some users UI elements, Some users UI elements, Some users UI elements, Some users UI elements, Some users UI elements")),
        //End of Merchant content
        Padding(
          padding: const EdgeInsets.all(12.0),
            child: ValueListenableBuilder < int > (
              builder: (BuildContext context, int height, Widget ? child) {
                return SizedBox(
                  height: height.toDouble(),
                  child: OttuCheckoutWidget(arguments: widget.checkoutArguments),
                );
              },
              valueListenable: _checkoutHeight,
            ),
        ),
        const SizedBox(height: 20),
          //Start of Merchant content
          const Padding(
            padding: EdgeInsets.all(12.0),
            child: Text(
              "Some users UI elements, Some users UI elements, Some users UI elements, Some users UI elements, Some users UI elements,"
              " Some users UI elements, Some users UI elements, Some users UI elements,"
              " Some users UI elements, Some users UI elements, Some users UI elements")),
      //End of Merchant content
    ])),
);

The code samples can be found here.

To access the actual code samples, navigate to the lib directory.

Additionally, the android and ios directories contain platform-specific code relevant to each respective environment.