A special feature of the month of Ramadan is that this month has three parts. In every part, Allah Ta'ala sends down His grace for His servants. In this regard, Hazrat Salman Farsi. Narrated from—
He said, the Prophet. On the last day of the month of Sha'ban, he stood among us as a Khatib, saying (the month of Ramadan) is a month whose first part is mercy, the middle part is forgiveness or forgiveness and the last part is release from Hell. That is, the first 10 days of the 30 days of Ramadan are for mercy, the second 10 days for forgiveness and the third 10 days for salvation. (Sahih Ibn Khuzaimah, 1887)
One of the good news given to the believer in this month is acceptance of prayers. The Holy Prophet He said, 'The prayers of three people are not returned. A just king, a faster—as long as he breaks his fast and is oppressed.' (Tirmidhi, Hadith, 3598)
Prayer is said to be the root of worship. This is why worship is incomplete without prayer. And it is Sunnah to recite suitable prayers to Allah on special occasions.
Since mercy is revealed during the first 10 days of Ramadan, one can pray to Allah for more mercy during this time.
In this case, this prayer described in the Qur'an can be recited. The prayer is-
وَقُل رَّبِّ اغْفِرْ وَارْحَمْ وَأَنتَ خَيْرُ الرّاحِمِين
Pronunciation: 'Wa kur rabbigfir war hum wa anta khairur ra-himeen.'
Meaning: 'And say, O my Lord! Forgive and have mercy, and You are the Most Merciful. (Surat al-Mu'minun, verse 118)
Or this dua can also be recited—
رَبَّنَاۤ اٰتِنَا مِنْ لَّدُنْكَ رَۡمَۃً وَّ هَیِّیٴۡ لَنَا مِنْ اَمْرِنَا رَشَدًا
Pronunciation: Rabbana a-tina milladunka rahmah, wahayyi'lana min amrina rashada.'
Meaning: 'O our Lord, grant us favor from You and arrange for us to conduct our affairs properly.' (Surah Kahf, Ayah, 10)