peaked with and some regional updates to Android 8.1 (Oreo) . By 2021, Lenovo had moved its update focus to newer generations like the Tab M10 and Idea Tab Pro series. How to Check for the Last Official Update
Since Lenovo did not release official Android 10 or 11 updates for the lenovo tbx704f android update 2021
To install these unofficial updates, you must follow a technical process that will and erase all data : peaked with and some regional updates to Android 8