[JIRA_CONFIG] Template fields alert manager --> jira integration does not work

Hellow!
Tried to use a new feature that allows to integrate Alertmanager with Jira without using jiralert https://github.com/prometheus/alertmanager/blob/main/docs/configuration.md#jira_config.
Encountered a problem that the “template” in “fields” is not readable, this is what my configuration file block looks like:

fields:
customfield_10002: "AB-123"
customfield_11314: [ { "key": "ABCD-123" } ]
customfield_11315: [ { "key": "ABCD-123" } ]
customfield_13707: '{{ template "jira.test.alertname" . }}'
customfield_13708: '{{ template "jira.test.namespace" . }}'
customfield_13709: '{{ template "jira.test.instance" . }}'

As a result when trying to send a notification, the sending happens, but the values are not read out and we get template names in the notification text, for example :
'alertname = {{ template 'jira.test.alertname' . }}'
namespace = {{ template “jira.test.namespace” . }}

And I want to get:
alertname = prod-123 (example)
namespace = monitoring (example)

Can you tell me if Alertmanager can't handle template in fields correctly or is there another construct for this?

Start with docs/configuration.md#jira_config and reproduce the reported fields configuration using the customfield values and template expressions shown in the issue. Trace how Jira notification fields are rendered and confirm that alertname, namespace, and instance values are substituted instead of being sent as literal template text.