Is the ḥadīth, "Do not refer to me as Sayyid (master) in your prayers," authentic, and is it better to say, "Allāhumma ṣalli 'alā Sayyidinā Muḥammad (O Allah, bless our Master Muḥammad)" in the prayer?

The phrase mentioned, "Do not blacken my face" (لا تسوِّدوني), is not a prophetic tradition (hadith) from the Prophet, peace and blessings be upon him, and scholars have clarified that it has no basis. As for the hadith, "I am the master of the children of Adam on the Day of Resurrection, and no boast," it is authentic. Referring to the Messenger, peace and blessings be upon him, as "Sayyid" (master) is permissible outside of theadhan (call to prayer), iqamah (second call to prayer), and prayer. However, in the adhan, iqamah, and tashahhud (testimony of faith) during prayer, a Muslim must adhere to what is stated in the Sunnah and not add to it, because acts of worship are based on divine revelation and specific instructions. Regarding the addition of the word "Sayyiduna" (our master) in the Ibrahimiyyah prayer (Salat al-Ibrahimiyyah), it is a matter of scholarly disagreement, and it is preferable to limit oneself to what has been reported in the Sunnah.