Is there an explicit prohibition of communal supplication after the obligatory prayers?

The Prophet, peace and blessings be upon him, forbade innovation in religion and warned against it. Every act that is not in accordance with his command, peace and blessings be upon him, is rejected and returned to its doer. This is indicated by the Hadith (definition) of Aisha, may Allah be pleased with her, that the Prophet, peace and blessings be upon him, said: "Whoever introduces into this matter of ours that which is not from it, it is rejected." And in a narration by Muslim: "Whoever does an act which is not in accordance with our matter, it is rejected." This Hadith is a great principle among the principles of Islam, as it explicitly rejects all innovations and inventions. Everything that is innovated in religion for which Allah and His Messenger have not given permission is not part of the religion in any way.