I've followed the directions at the Geoserver website here for installing the GDAL Image formats on Linux. However, afterwards there don't seem to be any entries to add ECW, MrSID, or JP2 rasters.
GDAL 3.0.4 is installed:
GDAL 3.0.4, released 2020/01/28
and the .jar files coped to the lib directory of GeoServer, and it has been restarted. Other GDAL raster formats now appear in the list of stores to add, but not the three I require the most. There is no error in the logs indicating an issue, either.
Is there possibly as step I missed?