You must create a shortcut of the app that you would like to add to start up. Drag and drop the app from the Start Menu to the desktop the shortcut of that app will be created on the desktop.
Figure 1: Creating a Desktop shortcut
Figure 2: Desktop Shortcut
Open Run command box by pressing the Windows logo + R keys. In the Run command field, type shell: Startup and then press Enter key to open Startup folder.
Figure 3: Run Command Box
Copy and paste the app shortcut from the desktop to this Startup folder and the app is added to startup.
Figure 4: Startup Folder