Hello there, @pro2022.
Let me share some insights about the languages supported in QuickBooks Online.
Currently, this is limited to some international versions only.
Supported languages:
- English
- Chinese
- Français/French
- Italiano/Italian
- Español/Spanish
That's why you're getting this kind of characters changed when converting the data from QuickBooks Desktop to QuickBooks Online.
Since every business has unique needs, especially in importing data, I recommend visiting the Apps Center. From there, you can choose one of the software applications that will help you import data files from QuickBooks Desktop with a different language.
Additionally, you can Google something like "convert data with Korean characters from QuickBooks Desktop to QuickBooks Online" to look for other conversion software. However, please be careful when choosing one to avoid compromising your data's security.
Feel free to reach us again if you have additional questions. I'll keep my notifications open. Stay safe and well!