Do you need an additional drop down box for one of your options? Sometimes you might have a side choice, such as Salad, that requires another choice, such as Salad Dressing.
Conditional add-ons are Extras, Toppings or Options that only appear after another add-on has been selected.
Example of a Conditional Add-On for Options
Ex: Customers can choose between a house salad or Caesar salad, if they select house salad they are then prompted to choose a salad dressing.

Originally the Salad Dressing choice doesn't appear, it is only once the House Salad is selected that the Salad Dressing becomes an option.

Example of a Conditional Add-On for Extras
Ex: Customers can choose to add a bag of chips to their sandwich for an additional charge, if they opt to add chips then they are then prompted to choose a salad dressing.

Originally the Chip Choice doesn't appear, it is only once Add a Bag of Chips is selected that the Chip Choice becomes an option.

If you need more information on add-ons in general, click here.
In your Online Ordering Console, you can set up conditional add-ons by selecting "Restaurant Manager" from the main menu, and then selecting "Menu Item Add-Ons" under the "MENU SETTINGS" heading.

From here, create both your add-ons as you usually would.
Next, click Manage Conditional Add-Ons.

Here you will see all the add-ons you have created. Find the primary add-on you want to use on the left hand side of the screen.

Select the conditional add-on you want to use from the drop down next to the primary add-on you wand to assign it to. Then click Save Changes.

Remember to assign the primary add-on to your menu item!