Show life above player minecraft?

Can you set a life indicator via the player, like with Hypixel, with one command?

Yes you can.

Only if you have installed the appropriate plugins.

Maybe this one still works:

https://dev.bukkit.org/...health-bar

Hypixel uses, I think, a private self-written plugin.

The mod does not show the lives above the player but if you look at it you can see the lives in the top left

http://www.9minecraft.net/damage-indicators-mod/