Hi there, silvia_m_gongora.
Thank you for joining the QuickBooks Community. I'd be happy to help get this taken care of today.
You can automatically import previous transactions for up to 18 months into QuickBooks Online.
For more information and detailed steps about Sync with Square, please check this out: Sync with Square Hub.
If you need to reach out for more help, our phone agents will be able to help you get to a resolution quickly. You can find our contact information on this link: Get help with QuickBooks Online.
That should do it. Drop a comment below if you have any other questions about importing your Square sales into QuickBooks Online. I'll be happy to help you out. Have a great day ahead.