Please see the reference from Sahih Al Muslim:
Translation of Sahih Muslim, Book : 4
KITAB AL-SALAT (THE BOOK OF PRAYERS)
Chapter 14 : THE TASHAHHUD IN PRAYER
Book 4, Number 0793:
'Abdullah (b.Mas'ud) said: While observing prayer behind the Messenger of Allah (may peace be upon him) we used to recite: Peace be upon Allah, peace be upon so and so.One day the Messenger of Allah (may peace be upon him) said to us: Verily Allah is Himself Peace.When any one of you sits during the prayer. he should say: All services rendered by words, by acts of worship, and all good things are due to Allah.Peace be upon you, 0 Prophet, and Allah's mercy and blessings.Peace be upon us and upon Allah's upright servants, for when he says this it reaches every upright servant in heaven and earth (and say further): I testify that there is no god but Allah and I testify that Muhammad is His servant and Messenger.Then he may choose any supplication which pleases him and offer it.
Book 4, Number 0794:
Shu'ba has narrated this on the authority of Mansur with the same chain of transmitters, but he made no mention of this: "Then he may choose any supplication which pleases him."
Book 4, Number 0795:
This hadith has been narrated on the authority of Mansur with the same chain of transmitters and he made a mention of this: "Then he may choose any supplication which pleases him or which he likes."
Chapter 15 : BLESSINGS ON THE PROPHET (MAY PEACE BE UPON HIM) AFTER TASHAHHUD
Book 4, Number 0803:
Abdullah b. Zaid-he who was shown the call (for prayer in a dream) narrated it on the authority of Mas'ad al-Ansiri who said: We were sitting in the company of Sa'id b. 'Ubida when the Messenger of Allah (may peace be upon him) came to us.Bashir b. S'ad said : Allah has commanded us to bless you. Messenger of Allah!But how should we bless you ? He (the narrator) said: The Messenger of Allah (may peace be upon him) kept quiet (and we were so much perturbed over his silence) that we wished we had not asked him.The Messenger of Allah (may peace be upon him) then said: (For blessing me) say: "0 Allah, bless Muhammad and the members of his household as Thou didst bless the mernbers of Ibrahim's household. Grant favours to Muhammad and the members of his household as Thou didst grant favours to the members of the household of Ibrahim in the world.Thou art indeed Praiseworthy and Glorious"; and salutation as you know.
Book 4, Number 0804:
Ibn Abi Laila reported: Ka'b b. 'Ujra met me and said: Should I not offer you a present (and added) : The Messenger of Allah (may peace be upon him) came to us and we said: We have learnt how to invoke peace upon you; (kindly tell us) how we should bless you.He (the Holy Prophet) said: Say: "O Allah: bless Muhammad and his family as Thou didst bless the family of Ibrahim.Verily Thou art Praiseworthy and Glorious, O Allah."
Please you may refer to this link:
https://www.iium.edu.my/deed/hadith/muslim/004_smt.html