Due to massive high tax conversion rates and for railway having a huge potential due to Brazil lacking free tier services/decent cloud solutions.
• Stripe (1.5%)
• PayPal (4.5%)
• MercadoPago (1.1% - 1.3%)
• PagSeguro (5%+)
*percentages are conversion taxes for USD -> BRL quickly taken from their support page.
The best option here would be to use Stripe as railway already uses it and they support native brazilian payment methods and as second option i would suggest MercadoPago for being extremely safe and one of the bests in Brazil.
And PayPal as a last resort as it is extremely fraudulent and has a terrible support in Brazil.

As payment methods listed from Stripe:
https://support.stripe.com/questions/accepted-payment-methods-in-brazil
"Boleto" is one of the most used payment methods in Brazil (and only in brazil), together with Credit Cards from Visa and MasterCard.