Here are the prefs to adjust:
On your Mac, clickLaunchpad>System prefs.
From there, clickKeyboard, and then clickKeyboard Shortcuts.
Next, selectFunction Keysfrom the left.

From here, toggleUse F1, F2, etc.
keys as standard function keyson, then click Done.
Why Use Mac Function Keys?

If you’ve ever used a keyboard shortcut, you know how simple and fast it is.
Some apps allow you to customize the function keys to fit your preferences.
you’re free to also change your function keys to match your own shortcuts by remapping them.

If there’s an action you take often using your Mac, the functions key can help.
Simply press the key to activate the function you better perform.
The function will automatically activate.

FAQ
Open theApplemenu and selectSystem Preferences>Keyboard>Keyboard Shortcuts>Modifier Keys.
Choose a function key and use the pop-up menu to designate an action for it.
If you ever want to change the function keys back to what they were originally, selectRestore Defaults.
Then press the function key you want as it appears in the Touch Bar.