Complete Guide required to setup slack with image notification on docker

Hi, There are so many problems and confusions regarding “Slack Notification” with an image. Having the same issue and no solution found yet.
Hereby I request all, anybody having working example of slack(with image and docker env and local storage)
Please share exact versions and step by step guide.
Requirement:

  1. Docker environment
  2. Renderer: External docker container / Phantom and IMP. storing images to a local machine( no s3,GC etc )
  3. Slack Notification with an image ( as we are getting in test alert)
  4. Grafana Image Version: Any working

If I am out of context/idea please let me know.