Which is better: prolonging prostration with supplication or supplicating after the prayer? And is it better to supplicate in the singular or plural form when in solitude?

It was not reported from the Prophet, peace and blessings be upon him, that he raised his hands and supplicated after the Taslim (salaam) of the prayer. Rather, what was reported from him was encouragement to supplicate dubur al-salat (after the prayer), and there is no objection to raising the hands during supplication in general. Supplicating in prostration (sujud) is better than supplicating after the prayer, as stated in the hadith: "As for prostration, strive in supplication therein, for it is most likely that you will be answered." It is permissible to supplicate using the singular form instead of the plural, and a Muslim can consider their situation in supplication, whether alone or in congregation. The Prophet's supplications in prayer were often in the singular form.