Hi there, @OJ7.
If you need to move your QuickBooks Desktop (QBDT) file to QuickBooks Online (QBO), you need to access your QBDT account first. This way, you can transfer your data file to QBO.
Since your computer was crashed, you can use your backup company data to restore your accounting files. This way, you can go back to one of your save points and continue what you're doing.
If you run into problems restoring your backup file, here's how to fix them.
Once done, you can now import your QBDT company file to QBO.
Please take note that you can only move a company file within 60 days after signing up to QBO. Also, some of your lists and reports won't be converted because of feature differences. You can check out more its information in this article: What to expect when you switch from QuickBooks Desktop to QuickBooks Online.
In addition, the articles that I've provided to you are tagged as United States since QuickBooks Desktop is only available in US, Canada, and United Kingdom.
I'm always here to help if you have any other concerns or questions. Just tag my name in the comment section and I'll get back to you as soon as I can. Have a great day.
Do you wish to migrate data from QBD 2017 UK version to QBO South Africa version, or else?