Open source is free, as in beer: you write code, nobody pays you. Of course, there are many ways to monetize your efforts, but there will be no direct cash payments from your users, usually. There are ways to collect money, which include an obvious “tip jar” button on your GitHub project page. The chances anyone will pay are low though. In my opinion, this is mostly because nobody trusts you enough — they are not sure you will use the money to make the product better. Most likely you will just spend it and nothing will change. But they want the product, not to make you happier. At least that’s what I feel when I see a Patreon button.