Open the Developer Tools of your favorite browser:
Chrome: You can open Chrome DevTools by opening the Chrome Menu (the vertical ellipsis) in the upper-right-hand corner of the browser window and select More Tools > Developer Tools. Alternatively, you can right click your mouse > inspect > console. You can also use the shortcut Option + ⌘ + J (on macOS), or Shift + CTRL + J (on Windows/Linux).
FireFox: You can open the Firefox DevTools via the menu by selecting Tools > Web Developer > Web Console. Alternatively, you can right click your mouse > inspect element > console. You can also use the keyboard shortcut Ctrl + Shift + I or F12 on Windows and Linux, or Cmd + Opt + I on macOS.
At the bottom of the open console, there will be a command line where you can type the following:
Hit Enter and the jQuery version will output.
NOTE: This is case sensitive so type it exactly as shown above.