if you want set hpbarfx to Player.hp
you should add to player container this hpbar
(you find container in sprite properties)
set width to: (hp/hpmax)*220 (220 this is pixel width)
when hp is full, your bar will have 220 px width
when hp i 1/2 your hpbar width will be 110
if you have only one variable 'HP'
set width to HP
(but when your hp will be 9999 your hp bar will have 9999px
so you can always add '/2' after set width to HP/2