If you run out of credits before your next billing cycle, you can purchase a one-time top-up. Top-ups are available to active subscribers only.
Several pack sizes are available. Exact pack sizes and pricing are visible in Settings > Billing & Plans once you are signed in. Only the account owner can buy credits, so if you were invited to an account as an agent, ask the owner.
Top-up credits land in your balance immediately and they do not expire. They stay until you spend them, even across a billing reset. If you consistently need more, upgrading your plan offers better value per credit.