I’m only getting option to install 4.20.3. 4.24 has the features to better translate models.
to get a new version of unreal engine, open the launcher and press the plus next to engine versions. I think the problem you are having is that you are not changing the version that you want to install. To do that click on the version of the engine and a menu should come up with other versions you can get.
Here is a video I made on how to do it
Let me know if you need more help