Is there a way I could LINK ‘labels’ (choices) of a drop-down to a LIGHTBOX (not a Page)?
Simply use either of these two existing tutorials show here.
Use dropdowns to navigate to another page on Wix - 8 lines of Code
https://www.totallycodable.com/example-dropdown-navigation
Redirect users using Dropdowns in Wix Code
And simply replace the page url with the lightbox url instead.
Wix Code Courses - Getting a Lightbox URL
https://www.wixcreate.com/adding-a-url-to-a-lightbox
https://support.wix.com/en/article/lightbox-appearing-in-site-url