Hi there,
Welcome to the Community. It's important you're able to get the support you need when migrating your data from QB Desktop to Online. Rest assured, I'll be glad to steer you in the right direction.
QuickBooks allows you to manually migrate your data from QBDT to QBO. I encourage you to check out the following article that shows you how to: Migrate from QuickBooks Desktop to QuickBooks Online with Intuit's internal tool. In case you need further assistance beyond the info provided in the article, I recommend contacting our phone support team again so they can share your screen and help make sure your data migration is seamless. For migration options that go beyond the advice provided by our support team, I suggest looking into third-party data migration apps on our app store: www.desktop.apps.com.
Let me know if you have other questions as you go through the article. I'll be a message away.