Currently, they can convert a company file from QuickBooks Desktop to QuickBooks Online for Malaysia, Singapore, Hong Kong and the Philippines through Odyssey. Please refer to the article below about importing a company file for more details. If not, you can find other third-party application providers to help you with the conversion.
Alternatively, you can export your lists from QuickBooks Desktop to QuickBooks Online. You can find the detailed steps about this in these articles:
Import or Export List Data in QuickBooks Online
Common Questions about Importing Data to QuickBooks Online