Shapefiles are the file type that is uploaded to your organization's Geography and will define your organization's service area.
Looking for information on how to add a Shapefile to your organization? Take a look at Adding Geographies.
SeeClickFix requires the full ESRI shapefile bundle for upload. That will include a .shp, .prj. and .dbf file (at a minimum), projected in WGS84 (SRID 4326) and all packaged as a ZIP archive. Additionally, the layers must be either a Polygon or Multi-Polygon (most typical), or a PolyLine (for streets).
We cannot accept files with Z or M features.
Here is a list of possible shape types, and our support for them. We suppose PolyLine and Polygon:
ESRI Shapefile Technical Description