If the upsell offers are not showing, make sure:
You’ve enabled the Woocommerce One Click Upsell Funnel Pro plugin. Navigate to the Global Settings and enable the plugin if it is disabled.
Your funnel is not in Sandbox Mode. If it is, edit the funnel and make it Live and Save Changes.
You are testing for the correct target product or category you’ve set in the funnel.
The offer page is published.
You’re making the payment through one of our supported payment gateways. If you make payments through a payment gateway that is not supported by our plugin, the offer will not be displayed.