Subscribe to data streams with a Cloud Node-RED Server

Prerequisites
You need to have a Cloud Node-RED server set up. If you haven't already, learn how to spin up a secure Cloud Node-RED server.
Also, if you currently don't have a device or client publishing data to a data stream, learn how to publish real-time messages to the cloud with Node-RED, Javascript, or Python. 
Connect to Cloud Node-RED Server
From the left side navigation in the console, navigate to the Cloud Node-RED Servers tab and select Node-RED Connect for the desired cloud server. Please note that only those team members with Organization Owner or Admin role can access the cloud servers.
Subscribe to Data Streams
Create an IoT API Key
To subscribe to real-time data streams with your Cloud Node-RED Server, you'll need to first create an IoT API Key. Only one API Key is sufficient to subscribe to multiple resources. From the left side navigation in the console, navigate to API Keys tab and select CREATE IOT API KEY. Choose a proper name, description, and permission level and hit SUBMIT.
Your API Key will be created and displayed. Take a note of the generated username and password or download them as a CSV file as these credentials won't be shown again. You'll need this API Key to subscribe to the real-time data streams from all your projects.
Configure the IoTFlows Nodes with the API Key
From the left palette in the Cloud Node-RED, drag and drop a datastream in node. Double click on the node, and tap on the edit button for the server.
Copy-paste the IoT API Key username and password that you generated in the last step and click Add. 
If the credentials are correct, you should see IoTFlows Cloud as the server. Click on refresh button to fetch the list of the data streams from your organization. Pick the desired data stream and hit Done.
Connect this node to a debug node and hit Deploy. You should see the data stream is connected to the server, receiving real-time messages that your other device/client is publishing, and showing them in the debug page.
Congratulations! You successfully subscribed to your real-time data stream in a cloud Node-RED server.