You can do it from terminal for exaple if you want
devel-su
vi /home/nemo/.local/share/system/privileged/connman/wifi_eduroam.config
paste it
[service_eduroam]
Type=wifi
Name=eduroam
EAP=ttls
CACertFile=/etc/ssl/certs/exampleCA.crt #path to your CA certificate (if you really need certificate)
Phase2=PAP
Identity=your email address
Passphrase=your password
Save file
for newer OS will be
vi /home/defaultuser/.local/share/system/privileged/connman/wifi_eduroam.config