Tashahhud
The details of prayer came from Sunnah, not from Qur’an. There is no basis for the claim that tashahud should be mentioned in the Qur’an. The dsrood we recite is also not there in the Qur’an. In tashahud we do not address the prophet. Traditionally, the direct address was kept as it is in the prayer. You can change it to third person as Assalam o Alaihi. No azkaar is compulsory to recite during the sitting position. You can choose any prayer.