You are attempting to update items on a trialing subscription with invalid options
You can't add or remove items for a subscription in trial, and you must use `do_not_bill` as the `proration_billing_mode` when updating quantities of existing items.
You are trying to update item quantities on a trialing subscription without proration_billing_mode: do_not_bill
You are trying to add an item to a trialing subscription
You are trying to remove an item from a trialing subscription
Ensure you are using
do_not_billwhen updating the item quantity on a subscription that is trialing.