Is it permissible to throw earth directly onto the face of the deceased when buried in a niche, and what is the correct way to bury the deceased in a niche out of necessity?

The method of "Shaqq" (trench grave) involves digging a trench in the middle of the grave, sized to fit the deceased. Its sides are built with bricks, and the deceased is placed within it on their right side, facing the Qibla (definition). Then it is roofed with stones, the roof is slightly raised, and then soil is poured over it. As for the "Lahd" (niche grave), it involves digging a niche at the bottom of the grave wall closest to the Qibla. The deceased is placed within it on their right side, facing the Qibla. Then this niche is sealed with unbaked bricks behind the deceased's back, and then soil is poured over it. Both methods are permissible by the consensus of scholars, but the Lahd is superior because it is how the grave of the Messenger of Allah, peace and blessings be upon him, was prepared, as narrated by Muslim from Sa'd ibn Abi Waqqas, may Allah be pleased with him: "Dig a niche for me and set up unbaked bricks over me, just as was done for the Messenger of Allah, peace and blessings be upon him." The soil is poured over the roof of the Shaqq or Lahd, not directly onto the deceased.