I think it just converts it to your own currency once you get to the paypal checkout or once it reaches your bank for Stripe payments. That is certainly how it has been for me when I buy games on itch that are priced in US dollars. I don't know where you are from but, for previous games, I've had people from all over the world buy them without difficulty so I do not think the currency would ever be an issue.
I hope this helps and thank you for your interest