I think you misunderstood the original post.
he is not asking for the payment method to be changed. you have games that you must BUY before playing, and this post is not about that.
The post is about games that are FREE, but allow you to donate or tip.
The vast majority of itch games are of this type, they are FREE games, but when you download the game, a dialog opens asking if you want to DONATE an amount of money.
It is difficult to know if you are going to give a tip or of what value, if you have not tried the game yet. The post is about that.