Sheikh Tusi in Misbaahul Mujtahid said: you should read the following if you wanted to send blessing to the Prophet (peace be on him and his descendants) on Friday:

بِسْمِ اﷲِ الرَّحْمٰنِ الرَّحِیْمِ

Bismillaahir-Rahmaanir-Raheem

In the name of Allah the Beneficent the Merciful.

اَللّٰهُمَّ اجْعَلْ صَلَاتَكَ، وَصَلَوَاتِ مَلَاۤئِكَتِكَ وَرُسُلِكَ، عَلٰى مُحَمَّدٍ وَاٰلِ مُحَمَّدٍ وَعَجِّلْ فَرَجَهُمْ۔

Allahumma aj‘al salataka, wa salawati mala’ikatika wa rusulika, ‘ala Muhammad wa ali Muhammad wa ajjil farajahum.

O' Allah let Your blessing and the blessing of Your Angels and the Prophets be on Muhammad and on the family of Muhammad and hasten their relief.

or you say:

اَللّٰهُمَّ صَلِّ عَلٰى مُحَمَّدٍ وَاٰلِ مُحَمَّدٍ، وَعَجِّلْ فَرَجَهُمْ۔

Allahumma salli ‘ala Muhammad wa ali Muhammad, wa ajjil farajahum.

O' Allah bless Muhammad and the family of Muhammad and hasten their relief.

It was reported that he use to recite the following (100) one hundred times:

اَللّٰهُمَّ صَلِّ عَلٰى مُحَمَّدٍ وَاٰلِ مُحَمَّدٍ، وَعَجِّلْ فَرَجَهُمْ۔

Allahumma salli ‘ala Muhammad wa ali Muhammad, wa ajjil farajahum.

O' Allah bless Muhammad and the family of Muhammad and hasten their relief