Is it permissible to supplicate for the deceased after their burial and the leveling of the earth while sitting or standing, and which is better?

The Sunnah for one who wishes to supplicate for the deceased after burial and leveling the earth is to do so while standing, following the action of the Prophet (peace be upon him). When he finished burying the deceased, he would stand over him and say: "Ask Allah for forgiveness for your brother and ask Him to make him steadfast, for he is now being questioned."