We did not pledge allegiance to the Prophet ﷺ on death. We only pledged allegiance to him that we would not flee.
حدثنا سفيان عن أبي الزبير سمع
لم نبايع النبي ﷺ على الموت إنما بايعناه على أن لا نفر
Its isnad is sahih, mentioned previously at 14046.