Add redis_exporter to Prometheus in pmm2

Hello,
Do you have to config PMM2 to monitor redis server via prometheus redis_exporter?

I search in blog and saw the link: https://www.percona.com/blog/2018/02/12/percona-monitoring-management-pmm-support-external-monitoring-services-yes/#comment-10971551

But it looks pmm2 doesn’t support external service yet?

I would appreciate if someone can share the solution.

Many thanks and best regards,
Shiron