In what manner should one seek forgiveness and supplicate for the deceased after burial?

There is no reliable hadith that specifies the manner of seeking forgiveness and supplicating for the deceased after burial. Rather, what has been reported is a general command to seek forgiveness and supplicate for their steadfastness. Thus, any form of seeking forgiveness and supplication for them is sufficient, such as saying: "O Allah, forgive him and make him steadfast upon the truth."