When you start IDE 2.x it will check if the installed platforms (board packages) are up-to-date. You can see that in the right bottom of the screen where a message like below pops up
Each platform (board package) has a list of boards; the maintainer of the platform (board package) decides which boards are in that list. In this case it's Espressif so you can contact them to add the board; if they will honour the request is an other question. The file where the boards are "defined" is boards.txt.
You can also add it yourself; if the board is totally different from anything else you will need to know exactly what you're doing. If the board is like the "ESP32S3 Dev Module" mentioned above you can make a copy of that entry in the boards.txt file and give it a new name.
Note that an update (by Espressif) of the platform (board package) will wipe those changes.