Is it permissible to supplicate with, "O Allah, grant me the serenity to accept the things I cannot change, courage to change the things I can, and wisdom to know the difference," and is it permissible to supplicate with words not reported from the Messenger of Allah, peace and blessings be upon him?

Supplicating with words not narrated from the Prophet or the righteous predecessors is permissible if their meaning is sound and does not contravene the Sharia, because supplication is not restricted to specific texts. Nevertheless, it is preferable to supplicate with the narrated prayers and comprehensive supplications. Asking Allah for well-being and its continuity suffices instead of the aforementioned supplication.