As a player from China,i really want to buy this game, but somehow my debit card does not support the current type of pucharse. Can you open the way of  "pay with paypal", please?

itch.io has a PayPal option when buying off their website so if you do not see it then it is a regional thing, not itch.io I live in the US

I cannot, paypal is evil and will ban people with no reason given forcing you to sue them to find out why.

Well, that's too bad. I'd like to buy the game but I don't have a credit card.

Well, gotta live with the demo then...