It will depend on how big your file is. Open your company file and hit f2 key. If you see your Total Targets < 350K, all your data will be migrated to QB Online. Otherwise, you should buy a 3rd party conversion service migrating data to QB Online. You can ask to migrate data including attachments.
https://quickbooks.grsm.io/Canada
https://quickbooks.grsm.io/CFIB
