Hi,
I think this feature request it's similar to https://help.locusgis.com/en/support/discussions/topics/47000670455 - please vote for the old one.
Support for raster images it's little bit tricky. It's something what we also want, but it isn't easy task as seems to be. Anyway, there is a workaround - convert raster into raster ,mbtiles in QGIS. Please see the article https://help.locusgis.com/en/support/solutions/articles/47001094929-how-to-import-geotiff-or-geopdf
Thanks, Petr
Gelda