@Wasim *******
Ok. The tangent here about a Brazilian passport is going to confuse loads of people.
Brazil along with a few other countries holds a special relationship with Thailand where their passport holders can get a visa waiver entry for 90 days. A visa waiver is completely different to a visa exempt entry. Semantics matter. With a waiver you cannot apply for an extension. You get 90 days and then you leave.
However you could (why would you?) apply for a tourist visa and pay for it and get 60 days on arrival. That can be extended for 1,900 baht once for a further 30 days.
If you bought a tourist visa already then so be it. You’ll get a 60 days stamp. The officer may overlook the fact that you have a visa and stamp you for 90 days anyway but that’s a coin toss.