Secret to store the Credentials of ArgoCD-Application-Repository

apiVersion: v1
kind: Secret
metadata:
 name: argocd-repo
 namespace: argocd
 labels:
  argocd.argoproj.io/secret-type: repository
stringData:
 type: git
 url: REPOSITORY-URL
 username: ACCESS TOKEN NAME
 password: ACCESS TOKEN

Creating ArgoCD Application

apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
  name: APPLICATION NAME
  namespace: argocd
spec:
  project: default
  source:
    repoURL: REPOSITORY-URL
    targetRevision: HEAD
    path: ANY FOLDER OF THE YAML MANIFESTS
  destination: 
    server: https://kubernetes.default.svc
    namespace: YOUR-NAMESPACE
  syncPolicy:
    syncOptions:
    - CreateNamespace=true
    automated:
      selfHeal: true
      prune: true

Creating a Secret to store the Credentials of Private Docker Registry

kubectl create secret docker-registry SECRET-NAME   --docker-server=registry.gitlab.com  --docker-username=GITLAB-USERNAME   --docker-password="ACCESS-TOKEN" -n YOUR-NAMESPACE