Recite the Niyyah:
اُصَلِّى سُنَّةَ الظُّهْرِ رَكْعَتَيْنِ مُسْتَقْبِلَ الْقِبْلَةِ أَدَاءًا لِلهِ تَعَالَى
"Uṣallī sunnatadh dhudhri rak'ataini mustaqbilal qiblati adā'an lillāhi ta'ālā"
Meaning:
I intend to pray two rak'ah of Sunnah Dhuhr, facing the qiblah, for the sake of Allah, the Most High.