@krobinson heard from a donor that when they use an English-language link like:
https://donate.wikimedia.org/w/index.php?title=Special:LandingPage&uselang=en&country=AR
when they get to dLocal, the form is in Spanish. I was able to replicate:
Can we review whether dLocal can catch the language preference from us, to continue in the language in which the donor commenced? Would typically be ES & PT-BR, besides EN.
OK, so their API doesn't actually have a language field in it. I found this line in an email from @Ppena when we were just getting started with them:
Astropay Hosted Page in English - not possible via mercado pago//waiting for their hosted page
I'll send an email to see if there's any new option available that would let us get a different language.
Still impossible according to our contact at dLocal:
I've checked with Product and unfortunately it's not possible to modify the checkout language. Our platform takes the user's country and shows the checkout in the corresponding language.
I have opened a ticket for Product Team for them to consider adding this to their pipeline.