Saving a custom template with humanize function in it, fails with the following error: Error: failed to save and apply Alertmanager configuration: template: mytemplate:2: function "humanize" not defined.
Template contents are:
{{ humanize (0.123456) }}
Grafana version: 9.5+
It doesn't look like a correct syntax. Try:
Doc: https://grafana.com/docs/grafana/v9.5/alerting/fundamentals/annotation-label/variables-label-annotation/