Open the blue TV app and navigate to the search menu. Hold down the microphone button on the remote control and give a voice command to say what you want to do.
If you are not in the search menu of the blue TV app when you hold down the microphone button and speak your search command, either Siri will be activated and search Apple for the corresponding content or the content of Apple+ will be searched without Siri. However, in either case, you will not see blue TV content.