Does not placing the palm fully on the ground during prostration – whether due to forgetfulness, ignorance, or intentionally – invalidate the prostration and the prayer?

Prostration is required on the seven limbs mentioned in the Hadith. The majority of scholars believe that prostrating on them is recommended, not obligatory, and it is sufficient to place a part of each limb during prostration. Therefore, the prayer of an Imam who does not place his entire palm during prostration is valid, and the prayer of those behind him is also valid.