@Jobungash Unfortunately, I don't have a screenshot of the page where I won the reward; I can only give you details of what the site looked like.
It was simply a short text message asking me to enter my phone number (registered with MiniPay) and its location, which in my case was the Colombian area code (+57).
When I entered the number, the space where I was supposed to reply changed to a "correct" icon, with a message saying that my reward would be deposited instantly into my MiniPay account upon identity verification via SMS, and that they would contact me if there was an issue.
And as I said yesterday, I never received a response from them.