OMG!!! It actually works.
I'll try it out, thanks @CorwinDev
EDIT----
Well, it actually shows BOLETO. But after filling all fields and press "PAY", it doesn't actually shows the Boleto to pay.

It should either shows a PDF/HTML page with the actual boleto, or show the barcode number, like this video shows:
https://youtu.be/uXNpltezZBM?t=101
The boleto is similar to this:

I'll try again using valid email address. Maybe Stripe sends an email with the boleto.
---Edit 2
Even with a valid email, it doesn't show the boleto neither Stripe sends an email with the Boleto.