The normal
DriveDX installation includes the utility necessary to access S.M.A.R.T. on USB drives, which is why I suggested re-installing DriveDX. As I recall, the utility is installed either as part of the initial install or the first time DriveDX is launched.
And yet, as I've said, DriveDx didn't see my external until after I installed SATSMARTDriver independently.
So, since kevs has already trashed and reinstalled DDx with no joy, it seems logical for him to try the independent installation.
And Github is hardly an "unknown" site.