You have to add predefined values to a single select attribute. To manage values for a single select attribute click on the "Attribute Values" link next to the attribute. On the other opened page that opens, there is a table with the attribute values of the related attribute. It is very similar to attribute table. You can view all added attribute values with their name, description, the status as active and default. Also, you can edit or delete with icons that appears with hovering on the related values. The values here are appearing in the dropdown respectively for single select type attribute. You can change the order of these values with the drag and drop method.
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