Generating MBTiles in QGIS3.4?

Similar to this question: Generating map tiles with QGIS 3.6?, how is it possible to create MBTiles from a raster ? (I operate QGIS 3.4 LRT)

I have tried Save As.... and selecting format: MBTILES, however the resulting file seems very small and generate an error when reimported in QGIS

I also have tried the plugin: Tiles XYZ. However I have always a 32kB result file which is empty when reimported in QGIS and after analysis seems to contain only one tile

• For reference, here are the parameters passed to plugin Tiles XYZ:*

Démarrage de l'algorithme 'Generate XYZ tiles (MBTiles)'…
Param: { 'DPI' : 96, 'EXTENT' : '131000,6000000,6764542,7965990 [EPSG:2154]', 'METATILESIZE' : 4, 'OUTPUT_FILE' : '/tmp/processing_7ayyyy/xxxx/OUTPUT_FILE.mbtiles', 'QUALITY' : 75, 'TILE_FORMAT' : 0, 'TRANSPARENT' : True, 'ZOOM_MAX' : 12, 'ZOOM_MIN' : 6 }