Set up and process Increase lockbox check deposits with automatic and approval-gated modes

Verified steps

1. Create a Lockbox object via the API, associating it with a specific Increase account and specifying check_deposit_creation as either automatic (checks are deposited immediately) or require_approval (checks queue for human or API review before submission)
2. Share the unique physical mailing address returned on the Lockbox object with payers who will send paper checks; this address routes mail to Increase's processing partner
3. Subscribe to the inbound_mail_item.created webhook to be notified when mail arrives at the lockbox; the event payload identifies the Lockbox and triggers your review workflow
4. For require_approval lockboxes, list pending Check Deposit objects via the API, inspect the front and back image URLs attached to each deposit, then POST an approval or rejection action to each Check Deposit before the bank cutoff
5. Monitor check_deposit.updated webhooks to track the deposit lifecycle from pending through submitted to returned; map return reason codes to remediation actions such as contacting the payer or re-presenting the item
6. Reconcile deposited check amounts against outstanding receivables by matching payee reference numbers embedded in check memo lines or MICR data returned on the Check Deposit object