If you are seeing a grayed-out/inactive "Continue to Add Filter"s button in the Create a Scan flow, it either means that none of the listed campgrounds under the Select Campground is selected with a check in the box (screenshot 1a & 1b below) or there are no campgrounds reservable in the park selected (screenshot 2 below.
screenshot 1a - Campgrounds are available but none are selected.
screenshot 1b - Campgrounds are available and at least 1 is selected.
screenshot 2 - Park is listed but no campgrounds are reservable.
What is happening with the last scenario?
Sometimes parks/campgrounds are listed on reservation websites even though they cannot be reserved through the reservation website. This can happen for a number of reasons. When this happens, the park/campground will returned in search results on CampScanner but will display like screenshot 2 above. There will be no selectable campgrounds under the Select Campground section in the Create a Scan flow and the green "Continue to Add Filters" button will be grayed out and inactive.,
Here is a short video to explain what might be going on.