Does casting spells thru mizzium armor allow for upcasting?

Mizzium Apparatus lets a caster cast a spell on their spell list for which they have a spell slot of the spells level to cast a spell that they don’t know, assuming a successful arcana check.. Per dmg pp141 "some magic items allow the user to cast a spell from the item. The spell is cast at the lowest possible spell level, doesn’t expend the users spell slots,and requires no components, unless the items description says otherwise".

This pretty clearly says that if i do not know the spell scorching ray, and i successfully use the Apparatus to cast it, it will cast as its native level.

Is this correct?