We will see in this article, how to resolve the 「Checkout ID not Found」 error you are seeing on your Checkout page.
Usually, this error message means that the CartFlows page ID does not match with the Page on which you have added the [cartflows_checkout] shortcode.
You may get this error message in two cases. Below are those cases.
Case 1: While editing the checkout page in your page builder
In this case, while editing the Checkout Page in the page builder, you may get this error message. Because in the page builder i:e editor mode of page builder, some WooCommerce functions are not available to access this error will be displayed.
Solution: To solve this, you just need to edit your checkout page and update the page and check the page by closing the page editor i:e. Exiting from the page builder.
Case 2: Shortcode misplaced
In this case, if the [cartflows_checkout] shortcode is placed on the other pages of WordPress or different pages which are not of the CartFlows.
Solution: To solve this error, you need to add the [cartflows_checkout] shortcode only on the CartFlows Checkout page and any other pages.
Note: This shortcode will not work on the CartFlows Upsell, Downsell, Optin, Thank you pages as well. It only works with the CartFlows checkout page.
Refer to this article to find on – Placing Shortcode in the Right Places!