Can you customize the app icons on the lock screen?

If you have a passcode or knock code enabled, disable it (set it to slide to unlock).

You can then customize the shortcuts (the menu will be there in the settings).

Then you can enable your passcode/knock code again. :)
 
If you have a passcode or knock code enabled, disable it (set it to slide to unlock).

You can then customize the shortcuts (the menu will be there in the settings).

Then you can enable your passcode/knock code again. :)

This!

I had the same issue until I disabled any security measure, then they became available.

I have this, coupled with GPS locations (so when I'm at home I don't need security). So when I'm at home, I have access to the shortcuts and I don't have to enter any codes. Great options. :)