Tax and accounting treatment for the bonus points granted to clients

Question:

A company, fiscally registered and for VAT purposes in Romania, paying tax on profit has as main activity the sale of agricultural products, own production. In order to stimulate sales, in December 2019, it implements a system of rewarding customers through bonus points, respectively at a second purchase of goods the client receives a reward from the company. The reward may be a discount of the invoice value or an additional quantity of goods in the category of those purchased, granted free of charge.

What is the tax and accounting treatment for the bonus points granted at the end of the financial year 2019 to clients, payable in the following year, respectively 2020?