There is so many cli:s now a days so I have a hardtime remeberd them all so here is a few basic ones.
argocd login
If the application in the same cluster as argocd is, the dest-server is correct. If you do bellow command from OCP it won't work due to root access
argocd app create guestbook --repo https://github.com/argoproj/argocd-example-apps.git --path guestbook --dest-server https://kubernetes.default.svc --dest-namespace argocd
argocd app get guestbook