How to turn off roaming but keep my Brazil data travel add on?

I believe, as long as you dont have any $$ in your wallet you are good.
Your plan coverage is what drives what is free/or paid ( using add on or wallet)

Text and voice do not work in South America with Fizz so your good to use your phone normally and use the data you bought !

Fizz is simple if you do not have the feature they won't bill

So if you go to brazil and have exemple a Minutes add on for Brazil Text and Data won't work

So don't worry!,

From what I heard, only data works in overseas now with your add on. No need worry about call , nor sms.

Make sure no money in your wallet.