Ali رضي الله عنه  reported: The Messenger of Allah ﷺ  said to me, “Recite:

‘Allaahummah-dinee wa saddidnee’

O Allah! Direct me to the Right Path
and make me adhere to the Straight Path.

Another narration is:

 ‘Allaahumma innee as’alukal-hudaa was-sadaada’
(I ask You for guidance and uprightness).

[Muslim 4/2090].

وعن علي قال : قَالَ لي رسولُ الله : « قُلْ
: اللَّهُمَّ اهْدِني ، وسَدِّدْنِي »
.وفي رواية :

 « اللَّهمَّ إنِّي أسْألُكَ الهُدَى والسَّدَادَ »
. رواه مسلم

Source: From Riyad-us-Saliheen : Dar-us-Salam English Publication