Apologies about this! We used to have usage-based pricing, but no longer do. That is the Stripe line item that authorizes usage based pricing.
We haven’t yet done the migration to remove it (requires a tricky refactor). That said, it will not be used, and you will not be billed for it.
(We’ve been crushed a bit by the inflow of users and haven’t been able to bring our head above water but plan on removing this as soon as we have a bit of bandwidth)