I'm trying to import control points using the Import Control Points button on the georeferencing tab within ArcGIS Pro 2.5.2. I have tried a few options and searched for the formatting it's looking for, to no avail. Each time, I get the error "The input file is invalid." I have tried PNEHC and PEN (P=point#, N=northing,E=easting, H=height,C=code), comma delimited. I also have a shapefile loaded in the project with the same points that I'm using for the control points. Specifically, what formatting is ArcGIS Pro looking for (order of coordinates, any preceding or following fields, delimiter, etc).