Use functions in a configuration in the same places you use a string
literal.
You can use examples in this topic as guidelines. This function results in a field label
with the localized string for
from:
<Label text="{$_i18n.from}">
This function results in a field label with the localized string for
since, followed by the
short string for the date
and time that occurred 24 hours
prior:
<Label text="{$_i18n.since} {$_format.dateTime($_now(-24),short)}">
For further examples, see the Extensibility
Samples.