Dxo Raw error message on import

Please can you help.Windows machine ,latest DXO RAW software,Lightroom classic latest version,New powerful laptop.The problem iI am having is that each time I try to export images for processing from lightroom to Dxo RAw I get the following error 1 of 1 image cannot be imported .These images are either not supported or have already been processed,or the files may be corrupted

What file format are you exporting from Lightroom? PureRAW can only work with original RAW files.

Thanks for the reply.The error indicates that the file is jpeg ,which needs to be in Raw as I shoot in raw.Could you please help me with the export settings that I should use in Lightroom and where I will find them
Many Thanks Ian

You cannot export a modified RAW file because they are immutable