Attempting to create an initiative bonus

I was working on a homebrew sub class, and I would like to give a proficiency bonus boost to the initiative roll. 

I attempted giving “ proficiency” to the initiative, but that had zero results. I then attempted to add a “bonus“ using the proficiency bonus as the source, and that was fruitless as well.

anyone have any tips, or know what I’m doing wrong?

Thank you for reminding me. 

i actually pulled up the Oath of the Watchers subclass and copied their modifier. It should work now. 

**Update: It didn't work.