OGR2OGR
ogr2ogr use the document
1. GeoJSON conversion ShapeFile
ogr2ogr -nlt POLYGON -skipfailures ground.shp ground.json
2. IGISMap also provide some format conversion tool
ShapeFile To GeoJSON: https://www.igismap.com/different-ways-to-convert-shapefile-to-geojson-online-or-offline-or-api/
ShapeFile To KML: https://www.igismap.com/shp-to-kml/