Read the info and download the Python script found at https://mp.uu.se/en/web/info/stod/it-telefoni/it-support/network-on-campus/eduroam/linux.
The installer puts the certificate at /home/cat_installer/ca.pem by default. Since the /home directory might be protected, it is recommended to move the file elsewhere. Create a file named eduroam.8021x in /var/lib/iwd/ and fill in your username and Password B, as in the example below.
# /var/lib/iwd/eduroam.8021x [Security] EAP-Method=PEAP