Did not get Product key when I got my Lenovo Laptop .

I bought a Lenovo laptop from takealot a month ago . At first I wasn’t aware it doesn’t have a product key because it didn’t require one after I bought it . It’s been a week now since it requires product key for my Microsoft 365 . And I don’t have it because I did not get it when I got my laptop . So what do I do ? Please help .