✅ Answer: Consider the following hadiths:

مُحَمَّدُ بْنُ یَعْقُوبَ عَنْ عَلِیِّ بْنِ إِبْرَاهِیمَ عَنْ أَبِیهِ عَنِ ابْنِ أَبِی عُمَیْرٍ عَنِ ابْنِ أُذَیْنَةَ عَنْ زُرَارَةَ عَنْ أَبِی جَعْفَرٍ أَنَّهُ سُئِلَ عَنْ رَجُلٍ صَلَّی بِغَیْرِ طَهُورٍ أَوْ نَسِیَ صَلَوَاتٍ لَمْ یُصَلِّهَا أَوْ نَامَ عَنْهَا فَقَالَ یَقْضِیهَا إِذَا ذَکَرَهَا فِی أَیِّ سَاعَةٍ ذَکَرَهَا مِنْ لَیْلٍ أَوْ نَهَارٍ فَإِذَا دَخَلَ وَقْتُ الصَّلَاةِ وَ لَمْ یُتِمَّ مَا قَدْ فَاتَهُ فَلْیَقْضِ مَا لَمْ یَتَخَوَّفْ أَنْ یَذْهَبَ وَقْتُ هَذِهِ الصَّلَاةِ الَّتِی قَدْ حَضَرَتْ وَ هَذِهِ أَحَقُّ بِوَقْتِهَا فَلْیُصَلِّهَا فَإِذَا قَضَاهَا فَلْیُصَلِّ مَا فَاتَهُ مِمَّا قَدْ مَضَی وَ لَا یَتَطَوَّعُ بِرَکْعَةٍ حَتَّی یَقْضِیَ الْفَرِیضَةَ کُلَّهَا

Al-Kafi, Vol. 3, p. 293

Zurarah narrates that he asked Imam al-Baqir about a person who has prayed without ablution, or has forgotten or overslept and missed some prayers. The Imam said: Whenever he remembers them, he should make up those missed prayers at any time of the day or night. But when the time for his daily obligatory prayer arrives and he has not yet completed the makeup prayers, he should continue making up the missed prayers until he fears the time for the current obligatory prayer will be missed. Then he should perform the current obligatory prayer, as it takes precedence. After that, he should make up the missed prayers, and he should not perform even a single supererogatory prayer until he has completed all the obligatory prayers he had missed.

مُحَمَّدُ بْنُ الْحُسَیْنِ الرَّضِیُّ فِی نَهْجِ الْبَلَاغَةِ عَنْ أَمِیرِ الْمُؤْمِنِینَ علیه السلام أَنَّهُ قَالَ

لَا قُرْبَةَ بِالنَّوَافِلِ إِذَا أَضَرَّتْ بِالْفَرَائِضِ

Nahj al-Balagha, p. 475

Imam Ali (peace be upon him) said: When supererogatory prayers harm the performance of obligatory prayers, no nearness to Allah is attained through those supererogatory prayers.

✅ Note: Based on these two narrations and other hadiths, it is recommended that a person first complete all their missed obligatory prayers, and then start performing supererogatory prayers.

✅ Important note: It has been observed that some believers, due to having missed prayers, refrain from performing supererogatory prayers in accordance with these narrations. However, they become negligent and lax in making up the missed obligatory prayers, and it takes years for them to complete the makeup prayers. It is recommended to diligently and earnestly complete the makeup prayers before the sudden arrival of death, and then engage in supererogatory prayers, as the emphasis of the Infallible Imams on supererogatory prayers is extremely great.