Thanks for letting us know what you need, @pirozbahy.
At the moment, the Price rule feature is only available in the US version of QuickBooks Online (QBO).
As a workaround, you can manually enter the price in the Rate column when creating an invoice. Alternatively, you could look for an inventory management app that is available in your area and can integrate with QBO
Get back to me here if you need more assistance in managing your transactions. I'll be there to help again.