Everything you make costs credits (the platform's unit of spend — each thing you make costs some). Kling's Credits Policy says the charge for a generation is whatever the screen shows at that moment, and its video guide prices video by the second: longer clips, higher resolution and generated sound each cost more. Credits come off when you press generate, and Kling's policy says that if a generation fails, they are refunded.
Credits do not all last the same length of time. Under Kling's Credits Policy, a membership's credits arrive each month and expire if you have not used them before their validity runs out; credits you buy separately last far longer, and are unaffected by whether you keep your membership. Kling spends whichever credits expire soonest first. None of them can be refunded or cashed out.
This page does not quote Kling's prices or say what any membership includes, because we have not yet verified them. Kling publishes them on its membership page — check there, and check whether a plan is a first-month offer that renews at a different price, before you pay. Memberships renew automatically until you cancel, and Kling's Terms of Paid Service say fees are not refunded once a paid service starts.
Whether you may use what you make depends on whether you pay. Read the security section below before you publish anything — this is the fact on this page most likely to matter later.