Optimus, also known as Tesla Bot, is a conceptual general-purpose robotic humanoid under development by Tesla, Inc. It was announced at the company's Artificial Intelligence (AI) Day event on August 19, 2021. CEO Elon Musk claimed during the event that Tesla would likely build a prototype by 2022. Musk is on record having said that he thinks Optimus "has the potential to be more significant than the vehicle business over time."

Tesla Bot is planned to measure 5 ft 8 in (173 cm) tall and weigh 125 lb (57 kg). According to the presentation made during the first AI Day event, a Tesla Bot will be "controlled by the same AI system Tesla is developing for the advanced driver-assistance system used in its cars" and have a carrying capacity of 45 lb (20 kg). Proposed tasks for the product are ones that are "dangerous, repetitive and boring", such as providing manufacturing assistance.

https://en.wikipedia.org/wiki/Optimus_(robot)
Given these paragraphs about the Tesla bot, where and when was it announced?
It was announced at the company's Artificial Intelligence (AI) Day event on August 19, 2021.