Navigate to Cloud Pub/Sub from the main menu, as shown in the following screenshot. Choose the Topics option under Pub/Sub:

Create a topic as shown in the following screenshot. A topic is like a category for messages that are sent/received between the applications:

Click on the menu button in the topic created and choose the New subscription option to create a new subscription to pull messages: 

Enter a name for the subscription and choose Pull as the delivery type, and then click on the Create button. This creates a subscription for messages of the type learningBigQuery:

Navigate to the Topics page and click on the menu button for the topic to send a sample message, as shown in this screenshot:

Enter the text for the message and the data to be sent with the message, as shown in the following screenshot. Click on ...