Dua for Asking Jannat

Anas bin Malik narrated that Prophet Muhammad (saw) said:
Whoever asks Allah for Jannat 3 times, Jannat says: O Allah, admit him into Jannat. So say

Allahumma inni Asaluka Al Jannat Al-Firdaus 

( Oh Allah, I ask you for Jannat al Firdaus)

Allahumma inni Asaluka Al Jannat Al-Firdaus 

( Oh Allah, I ask you for Jannat al Firdaus)

Allahumma inni Asaluka Al Jannat Al-Firdaus

 ( Oh Allah, I ask you for Jannat al Firdaus)