There are numerous ways to add push notification for android app which uses Amazon DynamoDB. Some of these include using Amazon Simple Notification Service (SNS), Amazon Pinpoint, or AWS AppSync. You can also use a third-party service like Pushy.
If you want to use Amazon Simple Notification Service (SNS), you first need to create a topic. Then, you can create a subscription to that topic, and specify the endpoint (which is the device token for your Android device). Once you've done that, you can publish a message to the topic, and it will be pushed to your Android device.
If you want to use Amazon Pinpoint, you first need to create a campaign. Then, you can create an endpoint (which is the device token for your Android device), and add it to the campaign. Once you've done that, you can send a message to the campaign, and it will be pushed to your Android device.
If you want to use AWS AppSync, you first need to create a subscription. Then, you can specify the endpoint (which is the device token for your Android device). Once you've done that, you can publish a message to the topic, and it will be pushed to your Android device.