Promtail parse timestamp

Hello.

I can’t parse this timestamp:
2020-12-17 05:26:06,006

here is my promtail.yaml
pipeline_stages:
- regex:
expression: ‘^(?s)(?P<timestamp>\d{4}-\d{2}-\d{2} \d{1,2}:\d{2}:\d{2},\d{3}) (?P<loglevel>\S+) (?P<content>.*)$’
- labels:
timestamp:
loglevel:
- timestamp:
format: “2006-01-02 15:04:05,000”
source: timestamp

But I get:

level=debug ts=2020-12-18T00:52:34.901025671Z caller=timestamp.go:196 component=file_pipeline msg=“failed to parse time” err="parsing time “2020-12-17 05:26:10,066” as “2006-01-02 15:04:05,000”: cannot parse “66” as “,000"” format=“2006-01-02 15:04:05,000” value=“2020-12-17 05:26:10,066”

How can I parse this timestamp as a timestamp ?