Do make sure you have correctly copied the appropriate "Reallusion" folder to Daz Studio.
So for example copy the Reallusion folder from iClone_Daz_Genesis_Extension_v4_IC7\DAZ Genesis Extension\Daz Genesis to iClone\Genesis8_Female to the location below (default install).
C:\Users\Public\Documents\My DAZ 3D Library\data\DAZ 3D\Genesis 8\Female\Morphs
Then make sure you restart Daz Studio for the changes to take effect. Now once you apply the Genesis8_Female_iCloneFaceKey.duf file to your character it should be correctly assigned. Then do the same for the Male character and Genesis 3 characters if required. Instructions are also supplied in the iClone_Daz_Genesis_Extension_v4_IC7.zip file.