The connection between Salesforce Products and QuickBooks Online products is a soft connection.
We have a detailed video that explains much of below. We recommend you watch this video at
Generally speaking, Salesforce Products and QuickBooks Online Items are treated independently and not synced. Instead, what we do is presume that a Salesforce Product and a QuickBooks Online Item are the same things if the names of the two are identical.
Best Practices - Salesforce is your system of Record for Products
One best practice is to have Salesforce as your system of record for Products. Why? Salesforce can have Multiple Pricebooks, custom fields, product families, and so much more. The only place to keep this rich data is in Salesforce. QuickBooks Online can only hold a subset of this data, so your system of record should be Salesforce.
(The exception to this is Inventory - QuickBooks should be where the inventory count is stored, as Salesforce has no native inventory management)
If you have lots of Products and Services in QuickBooks Online and need this in Salesforce, then you can use our import tool from the Breadwinner tab to bring in all your QuickBooks Products into Salesforce. We recommend you should do this just once, at the beginning of using Salesforce.
Best Practice - Have your Accountant Create new Items in QuickBooks
Ideally, ask your accountant to create new Items in QuickBooks. Why? Ites must have a Revenue/Ledge code associated with them. Your salespeople probably won't know what this should be. So have your accountant import them.
Alternatively, at the moment of Invoice creation, we will create products in QuickBooks if you don't have one already with that same exact name. Though it's best to set a default Revenue/Ledge code in Breadwinner settings.