5e OGL Sheet - HP Modifier, what on earth does this do???

I have been trying to figure out what in the heck this field does. At first I was excited and thought "OH! Maybe I can input a string to automatically calculate my character's Maximum Hit Points! Exciting!" but no matter what I put in either of the fields nothing seems to happen at all. What on earth is this for and how does it work?! <a href="https://i.imgur.com/BRJojBz.png" rel="nofollow">https://i.imgur.com/BRJojBz.png</a> I looked in the Roll20 help section found here -- <a href="https://wiki.roll20.net/5th_Edition_OGL_by_Roll20" rel="nofollow">https://wiki.roll20.net/5th_Edition_OGL_by_Roll20</a> I searched for forum topics on this, the only thread I found was this from February of 2019 -- <a href="https://app.roll20.net/forum/post/7181244/hp-modifiers-are-not-adding-hp" rel="nofollow">https://app.roll20.net/forum/post/7181244/hp-modifiers-are-not-adding-hp</a> I honestly have no clue what this HP modifier field is for and am curious if someone can clue me in on this.

Toughness Feat?

I was looking for a place to add the Tough feat, and thought this option (HP Modifiers) in the Settings tab on the sheet would do the trick.&nbsp; As the OP (and the thread he references) has stated, it does not appear to do anything.