How to edit Profic Bonus from using Ioun Stone of Mastery?

[Bernie]

I was told to do it this way 67488

But this adds the bonus to rolls. It does not "show" the change like on the Character Sheet Main tab 67489

Is it possible to do this?

[Zacchaeus]

No effect alters the character sheet. Most can be manually changed either by typing in a new value or by holding the CTRL key and using the middle mouse wheel; but proficiency bonus cannot be changed.

Incidentally you don't need SKILL: 1 since you have CHECK: 1. CHECK: 1 gives a +1 to all d20 ability checks and since skills are d20 ability checks CHECK: 1 will give a +1 to any skill check. As it stands you're giving the character a +2 to skill checks. You also have a slight issue with initiative since that is also a d20 ability check and so CHECK: 1 will give a +1 to initiative. Since your initiative bonus doesn't apply to initiative rolls you should include an effect of INIT: -1 to correct the +1 from CHECK: 1.

So the correct effect would be CHECK: 1; SAVE: 1; ATK: 1; INIT: -1 and if your character is a spellcaster then you'd also want SAVEDC: 1. You would also want to make sure that any special abilities that the character has (such as channel divinities) that require a saving throw that includes the proficiency bonus also get the +1 somewhere in the effect.