The Prophet (ﷺ) used to recite the supplication in the dawn prayer. The version of Ibn Mu'adh has the words: "sunset prayer".
Sunan Abi Dawud Book 8, Hadith 26
← Previous Hadith By Allah, I shall offer prayer like that of the Messenger of Allah (ﷺ). The narrator said: Abu Hurairah used to recite the supplication in the last rak'ah of the noon, night and dawn prayers. He would supplicate for the believers and curse the disbelievers.

Sunan Abi Dawud Book 8, Hadith 25 Next Hadith → The Messenger of Allah (ﷺ) recited the supplication in the night prayer for a month. He said (in his supplication): O Allah, rescue al-Walid b. al-Walid, rescue Salamah b. Hisham, rescue the weak believers; O Allah, trample severely on Mudar; O Allah, cause them a famine like that of Joseph. Abu Hurairah said: One morning the Messenger of Allah (ﷺ) id not make supplication for them. So I told him about it. He said: You dod not see that they have come (back).

Sunan Abi Dawud Book 8, Hadith 27