First the good news: the Wix Pay API for MercadaPago Argentina actually works (unlike the same for Wix Hotels). Good job.
Now a couple of issues, in order of importance:
1) the confirmation email is indeed in Spanish (ok), but the popup window asking for email, name, etc is still in English. Could you have a look at that?
2) although I have set
I do not get this Thank you Page. Maybe it has got something to do with MercadoPago windowed interface. I do get the "Successfull" message back, including ID and client data.
Happy with the result so far, hope you can iron out the above points.