Ask For Modifier

Good morning,

I'm trying to create an ask-for modifier that would give a free item once the order reaches $100. The modifier is not applying based on the order total, instead it is taking the List Price * Qty, and using this as the threshold for the modifier. I have tried differnent incompatiblities, buckets and precedence, and nothing seems to work.

Type: Promotion

Level: Group of Lines

Modifier Type: Promotional Goods

Volume Type: Item Amount

Thanks,