How to change 'Default Title' to 'Artwork Customization' in product options?

Hello,

We are using advanced product options to add custom variant options to our products. When we add these options, variants are added to our base products and then a dropdown with the text “Default Title” is visible on our shop’s product pages.

We would like to change the text in the dropdown to “Artwork Customization” instead of “Default Title”.

Here is the link to the site and a screenshot of the dropdown for reference.

https://johnpitre.com/