Appointments+ user GCal question

Hi team,
I am trying to configure the GCal API settings for Appointments+.
I have succeeded in hooking up one calendar to the main GCal tab for the plugin, but I would like to sync Service Provider calendars now. The problem is, I am unable to enter any information in the fields under each users settings. See the screenshot for an example.
Could someone help me fix this?
Thanks.