Supplication for protection from shirk
اَللّٰہُمَّ إِنِّيْ أَعُوْذُبِکَ أَنْ أُشْرِکَ بِکَ وَأَنَا أَعْلَمُ وَأَسْتَغْفِرُکَ لِمَا لَآ أَعْلَمُ
O Allah, I seek refuge in You lest I should commit shirk with You knowingly, and I seek Your forgiveness for what I do unknowingly.
References
[Sharah Ṣaḥiḥ Al-Adab Al-Mufrad No.551]