You can use any one or a mix of green leaves that can be consumed raw, i.e. spinach, fenugreek (methi), amaranth, mint, coriander, moringa, holy basil (tulsi), basil, beetroot leaves, betel leaves, lettuce, kale, curry leaves, arugula (rocket), dill, bok choy, microgreens etc.
Rotate the green leaves on a daily basis ie have a different green/mix of greens every day so that you get different nutrients.