Welcome and thank you for posting in the Community! I'm happy to share about reconciliation in QuickBooks Online (QBO).
Kubo is currently not on our list of supported apps, but if you're able to connect your QBO company to it, you may try doing reconciliations. You can ask their support team if they offer such a service so they can assist you.
Normally, you need to sign in to your QBO company in a browser so you can reconcile your accounts. If you're using mobile devices, you can open this link on your mobile browser and sign in: https://c11.qbo.intuit.com/qbo11/login?webredir