Is it permissible to supplicate in any prostration during any unit of prayer, or is supplication limited to the last prostration? And should the supplication be before or after the Tashahhud?

The positions for supplication (Du'a) in prayer are prostration (Sujud), between the two prostrations, and after sending blessings upon the Prophet (peace be upon him) in the final Tashahhud before the Taslim (salutation of peace). Supplication is also permissible after the Taslim and after completing the prescribed remembrances (Adhkar). However, prostration after the Taslim specifically for the purpose of supplication is not known. Supplication is legitimate in all prostrations of the prayer.