Don't Work in Web

[ARASHz4]

I got this error in web

ReferenceError: Toastify is not defined %3Canonymous%3E 1:30 dart-sdk/lib/html/dart2js/html_dart2js.dart 23474:33 append] dart-sdk/lib/html/dart2js/html_dart2js.dart 11768:14 add packages/toast/toast_web.dart 70:24 showWebToast packages/toast/toast_web.dart 42:5 showToast packages/toast/toast_web.dart 23:9 handleMethodCall dart-sdk/lib/_internal/js_dev_runtime/patch/async_patch.dart 84:54 runBody dart-sdk/lib/_internal/js_dev_runtime/patch/async_patch.dart 123:5 _async packages/toast/toast_web.dart 20:35 handleMethodCall packages/flutter/src/services/platform_channel.dart 547:55 _handleAsMethodCall dart-sdk/lib/_internal/js_dev_runtime/patch/async_patch.dart 84:54 runBody dart-sdk/lib/_internal/js_dev_runtime/patch/async_patch.dart 123:5 _async packages/flutter/src/services/platform_channel.dart 544:40 [_handleAsMethodCall] packages/flutter/src/services/platform_channel.dart 540:34 packages/flutter_web_plugins/src/plugin_registry.dart 115:33 handleFrameworkMessage dart-sdk/lib/_internal/js_dev_runtime/patch/async_patch.dart 84:54 runBody dart-sdk/lib/_internal/js_dev_runtime/patch/async_patch.dart 123:5 _async packages/flutter_web_plugins/src/plugin_registry.dart 106:38 handleFrameworkMessage lib/_engine/engine/platform_dispatcher.dart 607:7 [_sendPlatformMessage] lib/_engine/engine/platform_dispatcher.dart 350:5 sendPlatformMessage packages/flutter/src/services/binding.dart 456:36 send packages/flutter/src/services/platform_channel.dart 303:31 _invokeMethod dart-sdk/lib/_internal/js_dev_runtime/patch/async_patch.dart 84:54 runBody dart-sdk/lib/_internal/js_dev_runtime/patch/async_patch.dart 123:5 _async packages/flutter/src/services/platform_channel.dart 298:30 [_invokeMethod] packages/flutter/src/services/platform_channel.dart 483:12 invokeMethod packages/toast/toast.dart 65:32 show packages/orang_tracker/views/about/about_screen.dart 35:27 dart-sdk/lib/async/zone.dart 1661:54 runUnary dart-sdk/lib/async/future_impl.dart 147:18 handleValue dart-sdk/lib/async/future_impl.dart 784:44 handleValueCallback dart-sdk/lib/async/future_impl.dart 813:13 _propagateToListeners dart-sdk/lib/async/future_impl.dart 584:5 [_completeWithValue] dart-sdk/lib/async/future_impl.dart 657:7 callback dart-sdk/lib/async/schedule_microtask.dart 40:11 _microtaskLoop dart-sdk/lib/async/schedule_microtask.dart 49:5 _startMicrotaskLoop dart-sdk/lib/_internal/js_dev_runtime/patch/async_patch.dart 177:15 Error: PlatformException(error, Unexpected null value., null, null) dart-sdk/lib/internal/js_dev_runtime/private/ddc_runtime/errors.dart 288:49 throw packages/flutter/src/services/message_codecs.dart 652:7 decodeEnvelope packages/flutter/src/services/platform_channel.dart 310:18 _invokeMethod dart-sdk/lib/_internal/js_dev_runtime/patch/async_patch.dart 45:50 dart-sdk/lib/async/zone.dart 1661:54 runUnary dart-sdk/lib/async/future_impl.dart 147:18 handleValue dart-sdk/lib/async/future_impl.dart 784:44 handleValueCallback dart-sdk/lib/async/future_impl.dart 813:13 _propagateToListeners dart-sdk/lib/async/future_impl.dart 584:5 [_completeWithValue] dart-sdk/lib/async/future_impl.dart 657:7 callback dart-sdk/lib/async/schedule_microtask.dart 40:11 _microtaskLoop dart-sdk/lib/async/schedule_microtask.dart 49:5 _startMicrotaskLoop dart-sdk/lib/_internal/js_dev_runtime/patch/async_patch.dart 177:15