Here is an easy yet powerful dua-prayer from Quran if you want Allah to give you a baby boy or son. Asking Allah for a baby boy or a son in prayer (dua) is mentioned in Quran as Prophet Zakaria Peace Be Upon Him asked the Lord to give him a son as he wanted a heir who would become his inheritors after him.
رَبِّ لَا تَذَرنِي فَردًا وَأَنتَ خَيرُ الوَارِثِينَ
Transliteration: Rabbi la tazarni fardan wa-anta khairul wariseen
English translation: My Lord, do not leave me alone (with no heir), while You are the best of the inheritors (Al Quran - 21:89)
You can recite this dua as often as you can and reap the benefits in the form of a baby boy. When you sit down to make the dua, please make sure that you know the meaning of this dua and understand what this is all about.
Many times, we habitually recite duas and prayers in the Arabic language without even understanding what we are asking. Allah wants us to pray with all our heart.
Having a son is a great blessing (just like having a daughter is a great blessing), as the son usually becomes the inheritor of the parents and is expected to take care of his parents.
It is completely fine to ask Allah for a baby boy in your prayers/duas. Some people mistakenly think that asking Allah for a baby boy or son gives the impression that the parents don't want a daughter or don't like a baby girl.
I have seen many parents who willfully don't want a son so that they can tell the world that they are not greedy for the dunya as the son is usually expected to bring worldly ease and comfort to the parents.
To get 100% results, you must:
1) Have complete belief in Allah and His ability to bless you with a son.
2) Be patient as being impatience gives a negative signal to Allah and shows that you don't have full faith in Allah's abilities. If we don't trust Allah and His powers to fulfill our wish, then what's the point in making dua to Him in the first place?
3) Repent for the past and present mistakes and sins as we don't know when and where we have angered Allah unintentionally or intentionally. Allah usually makes life hard for us due to our own negligence and mistakes.
4) Start thanking Allah for His favours and blessings already being showered on us. Usually we ignore the present blessings, comfort, ease and favours in the pursuit of some future desires and end up becoming thankless to Allah as ignoring the present and current blessings from Allah is like ignoring Him and His acts of mercy upon us. So how can we expect to be thankful when He gives us blessings in the future if we don't bother to thank Him in the present moment?