Package pricing - Stripe

I am trying to use Stripe plugin by Bubble for tiered pricing subscription. I was originally planning to create a different product in Stripe for every tier, but I saw “package pricing” in Stripe.

Package pricing according to Stripe

Blockquote Select package pricing if you charge by the package, or group of units. For example, say you charge US$25.00 for every 5 units. Purchases are rounded up by default, so a customer buying 8 units would pay US$50.00.

I am passing the Quantity variable via Dropdown, but it is showing an error.

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