How is it read?
And some people say it’s a bidah, is it?
Thank you
Re: Namaze-e-Hajat.
Any two rakah nafl (supererogatory) prayer followed by sincere dua or supplication is recommended for all needs. Giving sadaqah when times are tough is also a great way to seek help from Allah swt.
However there is no such sunnah authenticated where there is a specific way to ask in times of Hajjah (need).
Wallahu Alam.
Re: Namaze-e-Hajat.
Peace life01,
So far I haven’t come across any hadith which specifically talks about “Namaz-e-hajat” that how, when and where to read it. There is a hadith No. 6498 of Sahih Muslim, from "The Book Pertaining to the Remembrance of Allah, Supplication, Repentance and Seeking Forgiveness (Kitab Al-Dhikr):
“Abu Huraira reported Allah’s Messenger :saw2 as saying that Allah, the Exalted and Glorious, thus stated: I live in the thought of My servant as he thinks about Me, and I am with him, as he remembers Me And if he remembers Me in his heart, I also remember him in My Heart, and if he remembers Me in assembly I remember him in the assembly, better than he (does that), and if he draws near Me by the span of a palm I draw near him by the cubit, and if he draws near Me by the cubit I draw near him by the space (covered by) two hands. And it he walks towards Me, I rush towards him.”
Furthermore, Almighty Allah said in Chapter 2 verse 186: “And when My servants ask you, [O Muhammad], concerning Me - indeed I am near. I respond to the invocation of the supplicant when he calls upon Me. So let them respond to Me [by obedience] and believe in Me that they may be [rightly] guided.”
Means whenever we are in need then we should calls upon HIM (Almighty Allah), because HE is more closer to us then we are. But by which method, act, or way can we calls upon HIM? To answer this, lets read the below Hadith No. 473 of Sahih Bukhari from the Book "To make the Heart Tender (Ar-Riqaq):
“Narrated Al-Mughira bin Shu’ba: The Prophet used to pray so much that his feet used to become edematous or swollen, and when he was asked as to why he prays so much, he would say, "Shall I not be a thankful slave (to Allah)?”
So basically our Prophet Muhammad 
thanking HIM (Almighty Allah) by praying Nafl namaaz which also bring us more closer to the Almighty Allah. Prophet Muhammad when asked why He prays so much even though His all sins were forgiven, He answered “shall I not be thankful slave (to Allah)?” So if we read first hadith and verse from Qur’an, we’ll understand that for our any needs, we must call upon Almighty Allah either by praying, doing zikar, by making supplications or in any other method, act, or way as per our easiness, but the best way is by praying Nafli Salah (namaaz).
I agree with what Antumul Alona wrote above. That is why we read Salatul Hajaat at any time. However, some says this salat should be read so and so and this to this time in this method, act or way, which is not proven from Hadith/Quran (as far my little knowledge) which is I found incorrect. Also there is a hadith in Tirmidi which talks about Salatul Hajjat and how to read it. I have no idea about that hadith whether its authenticate or not.
Almighty Allah knows best.