Transparent way to transfer and show all app payments go to charity

I'm thinking of creating an app (a game) for which I want all payments to go directly to a charity.

I also want this to be transparent as much as possible to users, e.g. maybe through a third-party page (i.e., not maintained by me) that shows the actual total amount gathered from payments and directed to the charity.

I want users to be sure their money goes directly where it's supposed to.

Is there an (easy) way to do it?

Greetings from Greece, celebrating 200 years of independence.

(background: I am mostly a C/C++/Python dev with little web knowledge and no knowledge of app development. I'm just starting to learn web/app development only to implement this idea, and I would like to know beforehand if this is even possible)