Kassey here from the Shopify Guru Team! Currently Mercadopago is not integrated with Shopify and cannot be used as a payment gateway. I'm sorry about that, Daniel! You can check out a list of payment gateways here that you can use! I would be happy to bring up the idea of using Mercadopago with our team and hopefully we will be able to see an integration with Shopify in the future!
I hope this helps, but if you have any further questions - be sure to reach out to our Shopify Support Team!
MercadoPago shows a simple integration on their support pages. Can anyone else can confirm this?