Not entirely sure this is the right forum for this, but it's pretty specific to Artificers so I guess it fits.

I'll be playing a one-shot next weekend with a 10th level armorer, We were allowed to choose 2 rare magic items so one of mine is the All-Purpose Tool. 

The item allows you to use a cantrip you don't know for 8 hours per day. For obvious reasons, I'd like to use Eldritch Blast, but I'm having issues adding the cantrip to my sheet. I tried adding it as a custom action/attack but I'm running into issues getting it right. If I set the range to "ranged" and the spell range to "ranged" I get the correct attack roll but it adds my intelligence bonus to the damage. If I remove the range setting but leave the spell range setting I get the correct damage but there is no attack roll button. If I remove the "int" spell ability setting I get the correct damage and there is an attack roll button but my intelligence bonus is not added to the attack bonus.

Any suggestions? Am I going about this entirely incorrectly?

Unfortunately they haven't found a way to build this feature of the item (and many others that add spells or abilities) to the database yet. Most of have created a Feat that does exactly what you'd normally take at an ASI level as well as the spell you want.

Here is the one I created (but Im not sure how to link it in a way to allow you to benefit from choosing it).

Feats can be added directly to a character sheet under Features & Traits->Feats->Manage Feats, so there’s no reason to double it up with an ASI like that.

Oh. Well there you go! I am not nearly as well versed in DnDBeyond as the forum's unicorn informer! Very good, carry on!

Quote from IamSposta >>

Feats can be added directly to a character sheet under Features & Traits->Feats->Manage Feats, so there’s no reason to double it up with an ASI like that.

 So I just had a look to modify my own character and the feat I made but I still can't get the benefit of the extra spell from an item. How would you achieve the additional spell from an item, 'Sposta?

Quote from Cyb3rM1nd >>

 Yeah cool. Thanks mate, thats exactly what I did and what I described in the second comment. Phew! Cheers.