Newbie question.  I've made two attempts at creating a Homebrew magic weapon and I'm missing something.  This is the what I'm trying to create; 

• Halberd of Vicious Cleaving (rare, requires attunement)- You gain a +1 bonus to attack and damage rolls made with this magic weapon. When you roll a 20 on your attack roll, the target takes an extra 7 damage of the weapon’s type. In addition, when an attack you make with this weapon reduces a creature to zero hit points, any excess damage from that attack carries over to another creature nearby. You can choose to target another creature within reach. If the original attack roll can hit it, apply any remaining damage to it.

Compared to a +1 Halberd I'm lacking the +1 to hit and +1 to damage modifiers.  Also, I don't know how to add the +7 slashing damage on a roll of 20 modifier (if that can even be encoded)   I've shared out both versions.  Can anyone explain what it's missing?

Thank you!!

The +1 to attack and damage is just Magic Bonus.

Modifier: Type: Bonus >> Modifier Sub-Type: Magic >> Fixed Value: 1.

The 7 on a roll of 20:

Modifier Type: Damage >> Modifier Sub-Type: Slashing >> Fixed Value: 7 >> Details: 20 on the Attack Roll.

Make sure you attune the item when testing.

Will do!  Thank you guys!