Hi Usman,
If the pair is just now 2 years old, then they are just now old enough to breed anyway. It doesn’t sound like they are bonded as a breeding pair. I would remove the nest box for now, because they are just using it as a bed. A nest box should not be hung until a pair has bonded as breeders and are mating or actively trying to mate. As for the nails, they should not be trimmed on either bird unless they are too long and curving around too much. Both birds need to be fully flighted with normal length toenails to have the balance to mate. You need to be feeding the a nutritionally balanced diet like pellets, and not a seed diet. They also need leafy greens, veggies and some fruit. To get them in breeding condition, they need an egg food – either a commercial egg food or cook an egg with the shell washed, crushed and cooked with the egg. They also need a private, quiet place for their cage and should be left alone as much as possible. Sometimes you can do everything right and still have no success. Not all birds are compatible and not all pairs will be good breeders. For now, rest the pair, offer the good foods and egg food, and observe them. Do not give the nest box back unless they are mating and seem ready to settle down and nest.
Thank you for asking Lafeber,
Brenda