If you are getting notifications from TravelSmart, then your Mac is infected with adware. TravelSmart is adware for Mac.
TravelSmart changes setting in your Mac. First, TravelSmart installs a browser extension in your browser. Then, after TravelSmart 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.