A family of Microsoft word processing software products for creating web, email, and print documents.
Assuming you are using the locally installed desktop software the Menu Bar is hidden if the document window is maximized [or Focus View] is being used. Move the pointer to the very top of the screen to access it or reduce the size of the window. If you prefer, use the macOS keyboard shortcut Control+F2 [or fn**+Control+F2**] to toggle display of the Menu Bar On/Off.