If you are getting notifications from TwinValley, then your Mac is infected with adware. TwinValley is adware for Mac.
TwinValley changes setting in your Mac. First, TwinValley installs a browser extension in your browser. Then, after TwinValley hijacks your browser, it modifies settings in the browser. For example, it changes the default home page, modifies search results, and displays unwanted pop-ups in your browser.