A single select block requires one item to be chosen as default.
It is recommended to keep the default option as the first choice/at the top of the variants.
HOW TO CREATE A SINGLE SELECTION BLOCK:
1. In an invisible section of your menu, create the sub-items/variations that will comprise the main item.
2. To create a selection block for the item, click on the plus (+) sign under the main product image.
2. Add a Title to the selection block, this needs to refer to the selection that is requiered . (Ex: ''Choose your pizza size'' - ''Size'')
4. A box with 'New Option for X' will show up, under the Option Type choose : ''Single Select''
5. To pull the sub-items/variations relevant to this item selection block, you need to click on the blue 'Existing Items as a Choice' selection (the option items were previously created under an invisible section)
6. Delete the first available option that appears as 'Choice Name'.
7. Choose a default (place it to be the one on the top of the options list)
8. Click Apply and then Save all Changes to save the changes, then Publish them with the green button on the left top of your screen.