How to add 1d4 to initiative.

I'm playing Cartographer Artificer and have the Adventurer's Atlas.  I tried to make a homebrew item and gave it the 1d4 bonus to initiative but it doesn't add it when I roll on the app.  I have the atlas in my inventory and equipped.  Is there a way to have it automatically add the bonus or do I just have to remember to do it myself?

It's not currently possible to do that with a homebrew item in D&D Beyond's homebrew system.

DDB homebrew stuff can add a bonus to a check if the bonus is a flat number, but not if the bonus is a die roll.

Remember that not only do YOU get the 1d4 but all of your map holders do as well. Most of that time that means you can equip the whole party (and possibly also your homunculus if you have a spare). It is a pretty solid buff to the whole party.

When I play, everyone just has to roll it, and then manually adjust initiative. 

Your homunculus doesn't roll initiative but it is super nice to be able to position it for portal jump.

Quote from FoolishMortal18588 >>

Remember that not only do YOU get the 1d4 but all of your map holders do as well. Most of that time that means you can equip the whole party (and possibly also your homunculus if you have a spare). It is a pretty solid buff to the whole party.

When I play, everyone just has to roll it, and then manually adjust initiative. 

Your homunculus doesn't roll initiative but it is super nice to be able to position it for portal jump.

 "Quick everyone grab hold of this map we're going into combat!"

Classic D&D gotta love it.

Quote from FoolishMortal18588 >>

Remember that not only do YOU get the 1d4 but all of your map holders do as well.

Just for the record, it's just people who have the maps who get the Initiative bonus. You can give yourself a map, and thereby get the bonus, but you don't have to.