No data, how to fill in the settings for it to work?

Well you need to fill in javascript selectors on the settings page. I think by default there are "defaults/placeholders" filled in at the settings page?
The selectors specify a certain element on for example the search page.

Sorting for example: You need to write a javascript selector that targets this element, for example a "select" element.

Does this help you?

I noticed a missing comma on the prefilled settings. In my case .view-exposed-form wasn't working.

.overview--search .views-exposed-form, #police-search-form-popup

Should be:

.overview--search, .views-exposed-form, #police-search-form-popup

.overview--search, .views-exposed-form, #police-search-form-popup

In your use case you safely remove #police-search-form-popup I guess. This has been in there for no reason. Will remove it ;-)

.overview--search, .views-exposed-form

And the probably the selector "overview--search" won't be there for you as well, I think.

closing ticket since I cleaned up the defaults in the form and this is resolved.