Zendesk integration with Flutter

I am creating mobile app with flutter and I want to integrate Zendesk SDK using flutter as i have done research and i get to know that zendesk can not provide support to hybrid apps the only provide native SDK but still there are plugins which provide support but its too older and not working for me below is the plugins which i have tried.

First Plugin

Second Plugin

Here is the code from second plugin

await Zendesk.initialize(<account key>, <application id>);

But I am not able to run app in android below is the error which i am facing

FAILURE: Build failed with an exception.

* What went wrong:
Could not determine the dependencies of task ':app:processDebugResources'.
> Could not resolve all task dependencies for configuration ':app:debugRuntimeClasspath'.
   > Could not resolve com.zendesk:chat:3.1.0.
     Required by:
         project :app > project :zendesk_plugin
      > Could not resolve com.zendesk:chat:3.1.0.
         > Could not get resource 'https://google.bintray.com/exoplayer/com/zendesk/chat/3.1.0/chat-3.1.0.pom'.
            > Could not HEAD 'https://google.bintray.com/exoplayer/com/zendesk/chat/3.1.0/chat-3.1.0.pom'. Received status code 502 from server: Bad Gateway
   > Could not resolve com.zendesk:messaging:5.1.0.
     Required by:
         project :app > project :zendesk_plugin
      > Could not resolve com.zendesk:messaging:5.1.0.
         > Could not get resource 'https://google.bintray.com/exoplayer/com/zendesk/messaging/5.1.0/messaging-5.1.0.pom'.
            > Could not HEAD 'https://google.bintray.com/exoplayer/com/zendesk/messaging/5.1.0/messaging-5.1.0.pom'. Received status code 502 from server: Bad Gateway
   > Could not resolve com.zendesk:chat-providers:3.1.0.
     Required by:
         project :app > project :zendesk_plugin
      > Could not resolve com.zendesk:chat-providers:3.1.0.
         > Could not get resource 'https://google.bintray.com/exoplayer/com/zendesk/chat-providers/3.1.0/chat-providers-3.1.0.pom'.
            > Could not HEAD 'https://google.bintray.com/exoplayer/com/zendesk/chat-providers/3.1.0/chat-providers-3.1.0.pom'. Received status code 502 from server: Bad Gateway

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 43s
Running Gradle task 'assembleDebug'...
[!] Gradle threw an error while downloading artifacts from the network. Retrying to download...

FAILURE: Build failed with an exception.

* What went wrong:
Could not determine the dependencies of task ':app:processDebugResources'.
> Could not resolve all task dependencies for configuration ':app:debugRuntimeClasspath'.
   > Could not resolve com.zendesk:chat:3.1.0.
     Required by:
         project :app > project :zendesk_plugin
      > Could not resolve com.zendesk:chat:3.1.0.
         > Could not get resource 'https://google.bintray.com/exoplayer/com/zendesk/chat/3.1.0/chat-3.1.0.pom'.
            > Could not HEAD 'https://google.bintray.com/exoplayer/com/zendesk/chat/3.1.0/chat-3.1.0.pom'. Received status code 502 from server: Bad Gateway
   > Could not resolve com.zendesk:messaging:5.1.0.
     Required by:
         project :app > project :zendesk_plugin
      > Could not resolve com.zendesk:messaging:5.1.0.
         > Could not get resource 'https://google.bintray.com/exoplayer/com/zendesk/messaging/5.1.0/messaging-5.1.0.pom'.
            > Could not HEAD 'https://google.bintray.com/exoplayer/com/zendesk/messaging/5.1.0/messaging-5.1.0.pom'. Received status code 502 from server: Bad Gateway
   > Could not resolve com.zendesk:chat-providers:3.1.0.
     Required by:
         project :app > project :zendesk_plugin
      > Could not resolve com.zendesk:chat-providers:3.1.0.
         > Could not get resource 'https://google.bintray.com/exoplayer/com/zendesk/chat-providers/3.1.0/chat-providers-3.1.0.pom'.
            > Could not HEAD 'https://google.bintray.com/exoplayer/com/zendesk/chat-providers/3.1.0/chat-providers-3.1.0.pom'. Received status code 502 from server: Bad Gateway

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 12s
[!] Gradle threw an error while downloading artifacts from the network. Retrying to download...
Exception: Gradle task assembleDebug failed with exit code 1

can any one please tell me how to solve this or any other way to integrate Zendesk with flutter speaker.

Thanks