✅Answer: In the book Mafatih al-Jinan by Shaykh 'Abbas Qumi, it is stated:

Fourth: A supplication with very lofty contents that is recited after the pilgrimage of each of the Imams (peace be upon them). Sayyid Ibn Tawus narrated this supplication in the book 'Misbah al-Za'ir' after this comprehensive pilgrimage, and that noble supplication is:...

✅Also, in the book Bihar al-Anwar, vol. 102, p. 169, it is stated:

ثُمَّ قَالَ السَّیِّدُ رَحِمَهُ اللَّهُ: دُعَاءٌ یُدْعَی بِهِ عَقِیبَ الزِّیَارَةَ لِسَائِرِ الْأَئِمَّةِ علیهم السلام اللَّهُمَّ إِنِّی زُرْتُ هَذَا الْإِمَامَ مُقِرّاً بِإِمَامَتِهِ مُعْتَقِداً لِفَرْضِ طَاعَتِهِ فَقَصَدْتُ مَشْهَدَهُ بِذُنُوبِی وَ عُیُوبِی وَ مُوبِقَاتِ آثَامِی وَ کَثْرَةِ سَیِّئَاتِی وَ خَطَایَایَ وَ مَا تَعْرِفُهُ مِنِّی.....

✅It is observed that the narration in both Bihar al-Anwar and Mafatih al-Jinan is from Misbah al-Za'ir by Sayyid Ibn Tawus, where it appears on page 244 of that book. The apparent meaning is that it is not attributed to the Ahl al-Bayt (peace be upon them), and Sayyid Ibn Tawus titles it as: 'This is a supplication that is recited after the pilgrimage of the other Imams (peace be upon them)...'

However, he does not in any way attribute it to the words of the Ahl al-Bayt (peace be upon them), and it has not been attributed to the Ahl al-Bayt (peace be upon them) in any other place. Therefore, it is not considered a traditional supplication from the Ahl al-Bayt (peace be upon them) and is not among the hadiths and narrations. We cannot, based on it, believe that reciting this supplication after the pilgrimage of the Ahl al-Bayt (peace be upon them) is a sunnah.

✅Insha'Allah, we should base all our beliefs and actions on the reliable and actionable narrations of the Ahl al-Bayt (peace be upon them) so that we may benefit from their reward.