Date formatting function (toTime function not available)

[m1sse]

Hello everyone. I've encountered an issue while using the toTime function in templates for sending messages on Telegram (templateFiles) with Alertmanager v0.26.0.

I need to format the StartAt time as "29/07/2022 09:42:29". Previously, when using an external bot, this worked like this, and there were no issues:
Date: {{ $val.StartsAt | str_FormatDate }}

I tried changing the function to toTime, which resulted in an error:
err="failed to parse templates: template: alerts.tmpl:31: function "toTime" not defined"

Looking through the repository, I can see that this function is not present:
https://github.com/prometheus/alertmanager/blob/v0.26.0/template/template.go#L170

I also see that it's present in Prometheus.

Is there a way to format the date in some manner?