How to activate a foreign eSIM in Nha Trang and which local SIM card to buy if your phone doesn't support eSIM?

If your phone doesn't support eSIM, it's easier to buy a regular physical local SIM card for internet in Nha Trang.

To receive the confirmation SMS for eSIM activation without paying for real roaming, just briefly turn on roaming on your home-country number, wait for the message, then turn roaming off again. Alternatively, ask someone still at home to forward you the code from the SMS.

After installing the eSIM you'll get a message like 'Welcome to [your country]! Tap the link to unlock Internet and SMS' - you should follow that link only after landing in Nha Trang, not before departure.