Hi there stevee.cda,
It's vital that all your inventory be correctly accounted for so that all your assets reflect the correct amounts. QuickBooks Online can connect to various other services through apps to be able to import information such as inventory items and transactions, I can provide some information about connecting apps to QuickBooks Online.
QuickBooks Online itself can't connect directly to Lightspeed, but there might be an app to facilitate this connection in order to have your inventory between the two software synchronized. In order to view the apps able to connect with QuickBooks Online, navigate to the Apps section of your QuickBooks. You can search for Lightspeed in this section to see if there are apps to connect to your services The connection might be able to be created directly from Lightspeed sight as well. For further information about if the connection can be created directly from Lighspeed's site, I recommend checking out their website or contacting their support team.
If you have any other questions, feel free to reach out here,