I need help. i cant import the sale invoices cos it says product doesnt exist. but when i checked my product list, its there.

Hello there, @kynethjane-kjabi. 

It is my pleasure to assist in importing invoices in QuickBooks Online.

When importing sales invoices, ensure that you use the default template. If yes, We can perform some troubleshooting steps to fix this. There are times when the browser is full of frequently accessed page resources, which causes some errors or unusual responses. 

Let's try accessing your account through an incognito window to rule out the possibility of a webpage issue. You can refer to these shortcut keys to open an incognito window in all supported browsers:

• Chrome: Ctrl+Shift+N
• Firefox: Ctrl+Shift+P
• Safari: Command+Shift+N

Once logged in, try to run a report. If it defaults to cash-basis, switch back to your regular browser. Then, clear its cache. This way, you can access QuickBooks with a clean slate. You can also use a different supported one.

Furthermore, if you wish to establish payment terms in QBO that allow you to offer discounts to your customers based on your agreement, check out this article: How to Adjust Invoice Payment Terms in QuickBooks Online.

If you require further help with adding your discount or managing your invoices, please feel free to leave a comment below. I'm here to assist you. Have a wonderful day!