I found it in page posts product
Hello,
Thank you for your comment and for using ‘Kaya QR Code Generator’.
If you want to display the qr-code by a widget, the generator is used by default.
Indeed, if you want to display the qr-code in a page, a post or a WooCommerce product, the generator is under the administration primary content of your page / post / product.
If the ‘Kaya QR Code Generator’ panel is not displayed, verify that ‘Kaya QR Code Generator’ is checked in the page / post / product options, in ‘Show more tools & options’ > ‘Options’ and ‘Advanced Panels’.
Please take the time to let me know about your experience and rate this plugin.