ModuleNotFoundError: No module named 'ase'

Good to hear. If you get a package that doesn’t have an Anaconda/conda recipe and yet exists on the Python Package Index (PyPI), you can use %pip install to do a similar process to install the package in the associated environment, see here for more about these related magic install commands. However, since Anaconda/conda/mamba is your main package manager it is best to stay with it as much as you can, which will enhance the stability and portability of the associated environments in the long run.