I was wondering if there is a way to add more than 3 attuned items to a character?  I have a Warlock in a homebrew-ish game and I am trying to figure out how to use dnd beyond to allow him to have more than 3.  I have the homebrew toggled to on but I can’t find an override or “allow more” anywhere.  
Thanks for your help. 

***edit***
if this is in the wrong place, please let me know and I will repost or move.  

You will need a feat or feature that allows the character to have more attuned items items. You can make a feat and use the Set -> Attunement Slots modifier to adjust it.

And then on the character sheet, use Features and Traits -> Manage Feats to add it to your character.

Or create a homebrew copy of the item but remove the attunement tag. 

So helpful thanks!!!

What is "the set"

I don't see it on the creation page

Quote from BrufusCragHammer >>

What is "the set"

I don't see it on the creation page

 Go to the feat creator

add a description and name. Save it.

Go to modifiers, click add.

Go to the modfiers scroll box, type in set.

Then go to the next box and look for attunement.

I did exactly this and it doesn't seem to adjust my Attunement slots. I set it to 6 and when i add the feat to my character, it's still only 4... HELP!

I'm having the same issue. The devs at beyond suck. They keep saying you can do something in their app but it ends up bugged so you can't, and instead of having a team working on fixing the bugs, they have all their people working on one dnd (which none of the people I've spoken to will play because they are ruining what makes all the races and classes special)

Here's a video showing how to do it.

There is a critical role feat that adds an attunement slot.