The shapefile format is a geospatial vector data format for geographic information
Shapefiles are a type of file format that contains vector features: points, lines, and polygons.
They consist of a collection of files with a common filename prefix, but with a number of different file extensions.
To import a shapefile into The Land App there must be at least 3 files, with the following extensions:
.shp, .shx, and .prj
a shapefile is likely to also contain .dbf
Make sure you can see all these files, you may have to 'unzip' or decompress a file before you can see the individual parts.
Then all you need to do is select the 4 files, which may look something like this:
manorfarm.shp
manorfarm.shx
manorfarm.prj
manorfarm.dbf
Then drag and drop all 4 files into the map in The Land App at once.