How to delete image from Firebase Storage?

You need to use this method call:

StorageReference photoRef = mFirebaseStorage.getReferenceFromUrl(mImageUrl);

Then delete as you were:

photoRef.delete().addOnSuccessListener(new OnSuccessListener<Void>() {
    @Override
    public void onSuccess(Void aVoid) {
        // File deleted successfully
        Log.d(TAG, "onSuccess: deleted file");
    }
    }).addOnFailureListener(new OnFailureListener() {
    @Override
    public void onFailure(@NonNull Exception exception) {
        // Uh-oh, an error occurred!
        Log.d(TAG, "onFailure: did not delete file");
    }
});

Use the function getReferenceFromUrl(URL)

FirebaseStorage firebaseStorage = FirebaseStorage.getInstance();
                    StorageReference storageReference = firebaseStorage.getReferenceFromUrl(pd.getUrl());
                    storageReference.delete().addOnSuccessListener(new OnSuccessListener<Void>() {
                        @Override
                        public void onSuccess(Void aVoid) {
                            Log.e("Picture","#deleted");
                        }
                    });