To integrate QuickBooks with Shopify, you will need to install the QuickBooks app from the Shopify App Store. Once installed, you will need to connect your QuickBooks account to your Shopify store. This can be done by entering your QuickBooks login credentials into the app. Once connected, you will be able to synchronize your Shopify store's financial data with QuickBooks, including sales, expenses and inventory. To complete the integration, you will need to set up your products, customers, and taxes in QuickBooks, and map them to your Shopify store.