Subscription renewal timing for credit-based AI video generation

We are assessing Fincra for luma dream machine, an independently operated text-to-video and image-to-video service that offers free credits and paid monthly or annual credit plans. We have not integrated Fincra.

Video jobs may take time to complete, so a payment renewal and a generation job can overlap. We would value guidance on three integration details:

Which verified Fincra event confirms that a recurring plan renewal has been paid and its next credit allowance can be granted?
If renewal webhooks are delayed or delivered more than once, which stable payment or invoice ID should be used for idempotency?
If a renewal is reversed while a video job is still processing, should the job reservation and restoration remain in our own usage ledger, with Fincra events used only for payment state?

Links to subscription-event and sandbox testing documentation would be useful.