This is what has worked for me at the University of Hohenheim (Stuttgart, Germany).
You need to enable developer mode on the Remarkable and access it via SSH (USB SSH access also works). I am not explaining how this works.
- Go to https://cat.eduroam.org and find a way to obtain a CA certificate and a wpa_supplicant configuration.
This is typically obtained by selecting Linux here. For my university, it will download a Python script called eduroam-linux-Hohenheim.py.
If I run it, even on macOS, it will generate two files in /Users/yourusername/.config/cat_installer, namely
ca.pemandcat_installer.conf. These are the two files you are looking for.
ca.pem has this form: