What should I ask Pierpaolo Barbieri?

I will be doing a Conversation with him, here is the opening part of his Wikipedia page:

Pierpaolo Barbieri (Buenos Aires, May 17, 1987) is an economic historian, researcher, Executive Director at Greenmantle^[and founder of Ualá, an Argentina-based personal financial management mobile app. He is the author of the book Hitler’s Shadow Empire: The Nazis and the Spanish Civil War. He has been featured in publications like Financial Times, New York Times, Foreign Affairs, El País, and The Wall Street Journal.

Ualá has been highly successful as of late in the payments space, including with the unbanked, and here is Pierpaolo on Twitter (mostly Spanish language).

So what should I ask him?