The wording mentioned does not appear in any hadeeth from the Prophet (blessings and peace of Allah be upon him). That has been stated by the scholars.
Imam al-Sakhaawi (may Allah have mercy on him) said: It has no basis. End quote.
Al-Maqaasid al-Hasanah, p. 135.
Ibn Hajar al-Haytami (may Allah have mercy on him) said: It has no basis. End quote.
Al-Fataawa al-Fiqhiyyah al-Kubra, 1/151
Most of those who compiled books of fabricated hadeeths agreed with them. See: al-Masnoo‘ fi Ma‘rifat al-Mawdoo‘, by al-Mulla ‘Ali al-Qaari, p. 205.
Many of the fuqaha’ have stated in their books that this hadeeth is rejected, as it says in Radd al-Muhtaar (1/513), al-Fawaakih al-Dawaani (2/359) and Nihaayat al-Muhtaaj (1/530).
The scholars of the Standing Committee said:
The hadeeth “Do not call me Sayyid…” has no basis, as was stated by the author of Kashf al-Khifa’. As for the hadeeth, “I will be the leader (Sayyid) of the children of Adam on the Day of Resurrection, and no boast,” it is part of a lengthy hadeeth that was narrated by Imam al-Tirmidhi from Abu Sa‘eed al-Khudri; he said: It is a hasan saheeh hadeeth.
As for calling the Messenger (blessings and peace of Allah be upon him) “Sayyid” in cases other than the adhaan, iqaamah and prayer, that is permissible because of the hadeeth quoted above.
With regard to the adhaan, iqaamah and tashahhud in prayer, one should say it as it is narrated in the Sunnah and not add anything to what is prescribed, because the adhaan, iqaamah and prayer are acts of worship, and worship is strictly to be done in accordance with the text of the Qur'aan and Sunnah, so it is limited to what is mentioned in the evidence. End quote.
‘Abd al-‘Azeez ibn Baaz, ‘Abd al-Razzaaq ‘Afeefi, ‘Abd-Allaah ibn Ghadyaan
Fataawa al-Lajnah al-Daa’imah (vol. 3/265)
With regard to the ruling on adding the word “Sayyidina” in al-Salaah al-Ibraaheemiyyah, it is one of the matters concerning which the scholars differed. We have mentioned above that it should not be said and that it is better to limit oneself to what is mentioned in the Sunnah, because prayer is an act of worship and is strictly to be done in accordance with the text of the Qur'aan and Sunnah, so nothing should be added to it except on the basis of shar‘i evidence.
And Allah knows best.