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