How do I track a player's Y axis height? (With no images please)

[TwiceOnce]

Please do not link me to chrysostom’s or SourApples’ tutorials, they have images to show wires and settings, the images don’t and won’t load because of the storage capacity. So can somebody please (without images to show anything of any kind) tell me how to measure a player’s Y axis, like the one in Don’t Look Down? Also, I’m inexperienced with the property and player coordinate devices.
Thank you!
Edit: Even though How do I make a height tracker? forum helped me to actually get it in my game, PhoenixWanderer’s reply helped me too =D

[PhoenixWander]

Those guides have broken images.

Anyways, here’s the short ver.

Coordinate device, which can make your Y a property.

Make a game overlay show that value