I have created topic and subscription base on this steps

To configure: Go to Google Cloud Console and create/select a project. On the header, click to open the menu and select ‘Pub/Sub’, or click https://console.cloud.google.com/cloudpubsub/topic/list Create/select a topic. Add the service account google-play-developer-notifications@system.gserviceaccount.com, and grant it the role of Pub/Sub Publisher. Create a subscription. There are 2 types of subscription:

• Pull: we need to configure our server to pull for new messages.
• Push: Similar to ios, the notification is send to the endpoint we configure. You can check here how to integrate PubSub with your server.

Also I have attached topic on my google play console in Set up monetization menu.

Configration successfully done and I have received acknowledgement mail from google API console.

My problem is I am receiving mail continues(like within 1 minute I have received 15 times Mail) so my server is down. how to reduce this mail? I only need mail while any user purchase or cancel or upgrate subscription.

Anyone have better solution than please give suggestion.

Thank you.