: If your MBTiles show a black background where they should be clear, check your alpha channel or PNG settings during the export.
: Select "Use Layer Extent" and choose your KML layer. convert kml to mbtiles
ogr2ogr -f GeoJSON output.geojson input.kml : If your MBTiles show a black background
You can use the gdal_translate function to convert your source data into a tiled format. and automated tiling.
Offers an online converter that handles data upload, projection settings, and automated tiling.