renovate/lib/modules/manager/argocd/readme.md

To use the argocd manager you must set your own fileMatch pattern. The argocd manager has no default fileMatch pattern, because there is no common filename or directory name convention for Argo CD YAML files. By setting your own fileMatch Renovate avoids having to check each *.yaml file in a repository for a Argo CD definition.

If you need to change the versioning format, read the versioning documentation to learn more.

Some configuration examples:

{
  "argocd": {
    "fileMatch": ["\\.yaml$"]
  }
}

{
  "argocd": {
    "fileMatch": ["argocd/.+\\.yaml$"]
  }
}

{
  "argocd": {
    "fileMatch": ["^config/applications\\.yaml$"]
  }
}