Options:
•Local SIM (cheap, at the airport or in stores).
•eSIM (Airalo, Holafly — activate in advance, convenient).
•Roaming (check tariffs, expensive).
•Wi-Fi (hotels, cafes — not for important things).
•International SIM (Drimsim, Globalsim — expensive but convenient). Tip: eSIM for internet + main SIM for SMS confirmations (bank). WhatsApp/Telegram work everywhere via internet.