kindly tell me why your invoice have no generated bar code

Hi, Zia. QuickBooks Online does not have a built-in feature to generate or display barcodes directly on invoices. This is a current limitation of the cloud-based platform, which is why they aren't appearing on your end. This feature is available by default in QuickBooks Desktop Enterprise.

While QuickBooks Online doesn't offer this natively, consider using a third-party application or integrating with QuickBooks to generate barcodes for your products. Simply go to the Integrations icon beside the Notification icon. Click Find Integrations. Type keywords or products that support the barcode scanner. 

Aside from logging into your account, you can also visit our QuickBooks App Store page.

In the meantime, you can use the SKU field in the Products & Services setup to help you keep track of your inventory. SKUs are alphanumeric and typically consist of eight characters, making it easier to manage your inventory. You can refer to the screenshot below, which shows where to add the barcode.

If you require additional assistance with processes and features in QuickBooks Online, please let me know in the comments below. I am here to provide more information about QuickBooks tasks.