In the name of God and prayers and peace be upon the Messenger of God, the Muslim should be careful to perform the prayer on time; For his saying - Almighty -: {The prayer was upon the believers as a timed book} [An-Nisa: 103], Muslim should take all the reasons that make him praying on time, if he wants to pray the dawn prayer on time, then he should sleep early and have the intention to do the prayer or to be helped waking up, or an alarm clock on time.
If he hears the call to prayer at dawn, he must rise from his bed and rush to his God’s pleasure. In order to begin his day by obedience and diligence; For saying - peace be upon him: {Satan held on rhyme head of you if it is a developing three contract hits each node you have a long night, if woke up remembering Allah, dissolved knots, when he does ablution (wudu,) 'unraveled knots, when he prays, unraveled knots, so he becomes an active person, a good at self ,Otherwise, he will become bad at self and lazy. ” (agreed upon)
If he didn’t listen to the call of prayer, taking the helping reasons into consideration, and wakes up after the sun rises, he can pray, and there is no sin on him. For saying - may God’s prayers and peace be upon him: {Whoever forgets a prayer, or sleeps over it, then it is an atonement for him to pray when he remembers it .. No atoning for it except praying it.} (TAHA 14 agreed upon).
As for how to do the two rak'ahs of Fajr after it is too late and the sun has risen: It is Sunnah for a person to start with the Fajr Rak'ahs, then praying the morning prayer. Because the judiciary appointed the performance, this is how the Messenger of God - may God bless him and grant him peace - did when he missed the morning prayer in one of his travels, and the Companions and he did not wake up until after sunrise.
Abu Dawad and others narrated on the authority of Abu Qatada that the Prophet - may God’s prayers and peace be upon him - was in a travel ....., and he said: “Keep our prayers upon us”, meaning dawn prayer, and they didn’t woke up, so they only woke up by the sun’s heat ..... They did ablution, and Bilal called for the prayer, and they prayed two rak'ahs of dawn, then they prayed dawn and rode on, and some of them said to one another: “We have overstretched our prayer, and the Prophet - may God’s prayers and peace be upon him - said:“ There is no fornication in sleep, but it is while you are awake, if someone forgot his or her prayers so he or she should pray them when he or she remembers them.
In the hadith is an indication that the Sunnah of Fajr have to be done before Because the Prophet - may God’s prayers and peace be upon him - ordered Bilal to call for prayer, then he prayed the the Sunnah (Sunnah of Fajr), then he ordered the establishment of prayer after that, so he prayed the obligatory prayer. Allah knows best.