I asked 'A'isha how the Messenger of Allah ﷺ did in the two rak'ahs as he (observed them) sitting. She said: He would recite (the Qur'an) in them, and when he intended to bow, he would stand up and then bowed.
قُلْتُ لِعَائِشَةَ كَيْفَ كَانَ يَصْنَعُ رَسُولُ اللَّهِ ﷺ فِي الرَّكْعَتَيْنِ وَهُوَ جَالِسٌ قَالَتْ كَانَ يَقْرَأُ فِيهِمَا فَإِذَا أَرَادَ أَنْ يَرْكَعَ قَامَ فَرَكَعَ
“Aishah narrated to me that the Messenger of Allah ﷺ prayed Witr with one Rak’ah, then he prayed two Rak’ah in which he recited while sitting, then when he wanted to bow, he stood up and bowed.”
كَانَ رَسُولُ اللَّهِ ﷺ يُوتِرُ بِوَاحِدَةٍ ثُمَّ يَرْكَعُ رَكْعَتَيْنِ يَقْرَأُ فِيهِمَا وَهُوَ جَالِسٌ فَإِذَا أَرَادَ أَنْ يَرْكَعَ قَامَ فَرَكَعَ
[Machine] I asked Aisha, and I said, "How did the Messenger of Allah ﷺ perform the two units of prayer while sitting?" She replied, "He would recite in them while sitting, and when he wanted to bow, he would stand up and bow."
سَأَلْتُ عَائِشَةَ قُلْتُ كَيْفَ كَانَ رَسُولُ اللهِ ﷺ يُصَلِّي الرَّكْعَتَيْنِ وَهُوَ جَالِسٌ؟ فَقَالَتْ كَانَ يَقْرَأُ فِيهِمَا وَهُوَ جَالِسٌ فَإِذَا أَرَادَ أَنْ يَرْكَعَ قَامَ فَرَكَعَ