Which platform will you prefer for publishing your online course

Several years ago I published my first book. It was rather small and more of a collection of rules than a big book. They helped me make a circulation of 1000 copies and I was able to sell them all. At first I thought that I could print my own work, but when I ran into my first problems with creating the cover and hardcover, I turned to the customer service at https://www.pissedconsumer.com/company/womans-world/ for advice. customer-service.html where I was told how best to make a circulation of such a volume. I decided to use their services, as it seemed to me that they had much more experience in this than I did.