If your Product Upsell offer has disappeared, it may be because a start and end date were put on the sale and it has ended. To reactive it, follow these steps:
- From "Shopify Admin", select Apps.
- Select Product Upsell.
- Select Current Offers.
- Select Edit next to the offer you would like to reactivate.
- Scroll down to "Step 4 - Select Offer Trigger".
- Adjust the end date in the Only make this offer available between a specified date and time range date fields or deselect this option entirely.
- Select Update.