Dua 20 This prayer is considered essential for expressing gratitude to Allah. It should be recited after every obligatory prayer.
(Surah Al-Ahqaf (46), Verse 15)

رَبِّ أَوۡزِعۡنِيٓ أَنۡ أَشۡكُرَ نِعۡمَتَكَ ٱلَّتِيٓ أَنۡعَمۡتَ عَلَيَّ وَعَلَىٰ وَٰلِدَيَّ وَأَنۡ أَعۡمَلَ صَٰلِحٗا تَرۡضَىٰهُ وَأَصۡلِحۡ لِي فِي ذُرِّيَّتِيٓۖ إِنِّي تُبۡتُ إِلَيۡكَ وَإِنِّي مِنَ ٱلۡمُسۡلِمِينَ

Rabbi awzi’ neee an ashkura ni’matakal lateee an’amta ‘alaiya wa ‘alaa waalidaiya wa an a’mala saalihan tardaahu wa aslih lee fee zurriyyatee; innee tubtu ilaika wa innee minal muslimeen.

My Lord! Inspire me to give thanks for Your blessing with which You have blessed me and my parents, and that I may do righteous deeds which please You, and invest my descendants with righteousness. Indeed I have turned to you in penitence, and I am one of the Muslims.

(Surah Al-Ahqaf (46), Verse 15)

At the beginning of this verse, Allah the Almighty guides humans to behave with gentleness and love towards their parents, to honor them, and to pray for them. Allah has made obedience to parents obligatory.
Our beloved Prophet Muhammad (S.A.W.) said: "Allah is pleased with those who are dutiful to their parents." Therefore, this dua should be recited after obligatory prayers.