Can not update data image

I try to update data, but it can not save an image, but other data is succesfully updated. Just image doesnt uploaded.

This is my controller Update method

 public function update(Request $request, $id)
    {
        $leaders = Leader::findOrFail($id);
        $leaders->update($request->all());

      if ($request->hasFile('photo')) {
            $file = $request->file('photo');
            $timestamp = str_replace([' ', ':'], '-', Carbon::now()->toDateTimeString());
            $fileName = $timestamp. '.' .$file->getClientOriginalName();
            $leaders->photo = $name;
            $file->move(public_path().'/images/img_lead/', $fileName);
            $leaders->save();
        }
    return redirect()->route('actorlead.index');
} ```