scoreforge character sheet - how to add the "black blade" for the bladebound magus?

[aza9999]

I'm building a bladebound magus and trying to add my black blade at level 3. I can't see anywhere that you add it other than to make a normal scimitar +1, and add alertness to the magic buffs tab.

Is there a specific way to add it that i've missed or is it only able to be done manually in a round-about way like i'm doing?