4.1.5 - How Make Monsters/ Boss Life HUD?

I'm making a platform game, and I already have at least two levels finished with boss and everything. To top it off, I would like to know if anyone knows how to make the boss's health appear, and remove it with each hit of the player?

Would it be like the player's health, linking the variables directly with the Boss sprites?

Thank you very much in advance.

Use a new variable (for example "bossHealth") that you will modify each time a monster is hurt (handle monster hurt script). Like the small code joe explained for other variables in the HUD.

EDIT: forget everything I wrote above... I did read 4.5
Hmm... for the 4.1.5, it's more complicated. You could use a HUD variable... and modify it each time your monster boss is hurt. But the problem is it also means this hud will always be displayed.
It requires too much customizations in the default script in order to work correctly