Hi, I'm Brazilian, I live in São Paulo, and I'd like to start practicing "dumpster diving." The "problem" is that I don't know how it works here; I've looked for dumpsters, but they all seem to be locked.
Back in the day, companies used to buy the locks in bulk so they only needed one master key for all of their dumpsters. I used to have a few for our businesses. Not sure if they do that in Brazil though.
You're gonna have a hard time in Brazil, as well as many developing countries.
People actually trash pick at the city dumps professionally. These folks even form gangs and protection rackets over picking and selling garbage.
Most of us in the sub won't have much advice other than the basic "see a dumpster and look inside".
Back in the day, companies used to buy the locks in bulk so they only needed one master key for all of their dumpsters. I used to have a few for our businesses. Not sure if they do that in Brazil though.
https://www.thelocksource.com/blogs/welcome-to-the-lock-source-your-new-source-for-locks-padlocks-and-electric-strikes-for-access-control/how-to-find-your-key-number-for-master-lock-padlocks