WooPOS exports general ledger to IIF file when you do dayend.
You can then import to QBO through an app like this:
https://support.transactionpro.com/kb/a19/importing-iif-journal-entries-quickbooks-online.aspx
You can also upload all transactions to WooCommerce and use a WordPress plugin to connect to QBO.
WooPOS has many reports, you can just print a sales summary report one a year and manually type into QBO. I think this is the easiest way and won’t cost anything.