pfSense » pfSense Docs

A few extra notes from an overlapping entry in the internal Redmine:

The book still shows you can only use admin but that is no longer true:
https://docs.netgate.com/pfsense/en/latest/book/highavailability/example-redundant-configuration.html#configure-configuration-synchronization-xml-rpc

The 'wiki' docs do not say that but only use the admin user as an example:
https://docs.netgate.com/pfsense/en/latest/highavailability/configuring-high-availability.html#enable-state-synchronization-pfsync

Importantly nowhere mentions that the user used MUST either be the admin user or have the 'System HA node sync' privilege. Being in the default admins group in not sufficient.