You should select one of the environments made available by the ACCESS-NRI team. There is no need for you to generate a list of available environments because they’re all available in the dropdown list you show in your screenshot. Simply click on that box where it says Python 3 (ipykernel) and a list of all available environments will appear. If you scroll up, you’ll find the different versions of analysis3. I chose the latest analysis3-25.04. Below, I’m highlighting the boxes I clicked to get this list.
The link I shared above has some information about the different environments, but you can also refer to the release notes here.
The ants package appears to be available on analysis3-25.04 based on this repo. But the docs on the previous paragraph have instructions on how to request a package that is not available in the conda environment.