You've reached the right place for help. It's important you're able to import your invoices and I'd be happy to steer you in the right direction.
You'll need to use a third-party to successfully import a quote/estimate to your QBO account. Among other apps, there's a third-party app on our app store which allows you to import estimates. Here's a link to the app: Transaction Pro. Give this app a try and let me know how you make out. I also recomend searching for other similar apps on our app store using this link: QBO App Store.
In case you've got other questions, don't hesitate to reach out. I'm here to help. :)