Hit that button at the bottom, ‘Export Retarget Assets’. That will create RTG AutoGenerated in a folder that you choose. You open that ‘RTG AutoGenerated’ and replace the autogenerated IKRig for Daz and Metahuman with the ones already in UE5.4 (assuming you activated the Daz and metahuman plugins). I hope these two pics make it a bit clearer. Look on the far right for the IKRigs I am talking about.
