Hey, 

So my DM, for roleplay reasons, gave me an extra +1 to my proficiency bonus. I didn't level up or anything. it's strictly roleplay related. Is there a way to add that +1 to my proficiency bonus on my character sheet? I couldn't find a way. 

You'd have to create a feat or magic item that gives you +1 to proficiency or proficiency skills. There's no way AFAIK to directly modify proficiency

Also, that's a very powerful bonus

Genius! THanks for the help dude! I created a new feat that applies a +1 bonus to my proficiency score. Worked perfectly!

add a ioun stone of mastery to your inventory and attune the item to add the +1 to your proficiency bonus

How did you do that? I can't seem to find the option

I know this is 4 years later, but I found it lol. 

It is in Modifiers > Bonus > Set Proficiency Bonus 

Thx