Remove Software Update Notification in System Preferences on macOS Mojave 10.14.6

I received a notification that macOS Catalina is available for downloading , but I don't want to download or update my current operating software. However the Software Update icon in System Preferences shows 1 update available and I want to remove this notification - please see attached screen shot.

I have tried to find how to do this on the internet and all posts direct me to the App Store icon in System Settings. My System Preferences does not have this icon.

Can someone please guide me in removing this notification.