Please i need help for Advanced in Financial Accounting. Thank you.

Q. 2) 10 marks A local car repair shop gives its customers two loyalty points for every dollar spent in their shop. Customers are allowed to redeem these points in blocks of 1,000 for a free oil change that would normally cost the repair shop $40. During December, 2022 its total sales were $135,000. Only 45% of the customers redeem their loyalty points. You are required to calculate the amount of liability that need to be provided by the repair shop and also provide necessary journal entry.