Flutter

import 'package:dodopayments_checkout/dodopayments_checkout.dart';

// showSuccess(), showFailure(), showExpired(), and reconcileAbandonedSession()
// are your own functions. See Abandoned Sessions for what to reconcile.
final result = await DodoCheckout.instance.start(
  CheckoutParams(
    checkoutUrl: Uri.parse(checkoutUrl), // from your backend's checkout session
    returnUrl: Uri.parse('myapp://checkout/return'), // scheme must be registered (see Installation)
    onEvent: (event) => print(event.type), // logging only
  ),
);

switch (result.status) {
  case CheckoutStatus.succeeded: showSuccess(result.paymentId);
  case CheckoutStatus.failed:    showFailure();
  case CheckoutStatus.cancelled: await reconcileAbandonedSession(); // outcome unknown, not a failure
  case CheckoutStatus.pending:   await reconcileAbandonedSession();
  case CheckoutStatus.expired:   showExpired();
}

import 'package:dodopayments_checkout/dodopayments_checkout.dart';
import 'package:flutter/material.dart' show Color;

final result = await DodoCheckout.instance.start(
  CheckoutParams(
    checkoutUrl: Uri.parse(checkoutUrl),
    returnUrl: Uri.parse('myapp://checkout/return'),
    customization: BrowserCustomization(
      android: AndroidBrowserOptions(
        toolbarColor: Color(0xFF6366F1),
        closeButtonStyle: CloseButtonStyle.back,
      ),
      ios: IosBrowserOptions(
        presentationStyle: PresentationStyle.fullScreen,
        colorScheme: BrowserColorScheme.dark,
      ),
    ),
  ),
);

import 'package:dodopayments_checkout/dodopayments_checkout.dart';

final abandoned = await DodoCheckout.instance.getAbandonedSession();
if (abandoned != null) {
  // Ask your backend for the outcome of abandoned.sessionId, and show it.
  // Clear the record only after the outcome is final:
  await DodoCheckout.instance.clearAbandonedSession();
}