'Astaghfirullaahal-'Adheemal-lathee laa 'ilaaha 'illaa Huwal-Hayyul-Qayyoomu wa 'atoobu 'ilayhi.
I seek the forgiveness of Allah the Mighty, Whom there is none worthy of worship except Him, the Living, the Eternal, and I repent to Him(Allah will forgive him even if he has deserted the army's ranks.)