EU based company selling premium subscription in Brazil

can anyone explain how we should handle tax documentation on sales done to Brazilian users. Apple documentation is close to none. We have one problem that we need to address: subscriptions are now less than half the price of europe. We will review it. In europe one year is sold by 89,99. In Brazil it is around 40 eur. Then we also see the brazilian monthly reports marked red/negative (we normally pay, not receive payment). And we have yearly tax docs for brazil that honestly I have no clue what to do with. Anyone has experience on this matter?