Similar to this rather dated question, is there a way to generate map tiles on QGIS 3.6? The plugins linked from that question only support QGIS 2.x. I wonder if things have changed in QGIS 3.x rendering plugins unnecessary.
In processing You can find gdal2tiles script. More info to find on gdal.org. From the description
This utility generates a directory with small tiles and metadata, following the OSGeo Tile Map Service Specification. Simple web pages with viewers based on Google Maps, OpenLayers and Leaflet are generated as well - so anybody can comfortably explore your maps on-line and you do not need to install or configure any special software (like MapServer) and the map displays very fast in the web browser. You only need to upload the generated directory onto a web server.
GDAL2Tiles also creates the necessary metadata for Google Earth (KML SuperOverlay), in case the supplied map uses EPSG:4326 projection.