In order to access the server UI you have the following options:

1. kubectl port-forward svc/argocd-server -n argocd 8080:443

    and then open the browser on http://localhost:8080 and accept the certificate

2. enable ingress and check the first option ssl passthrough:
    https://github.com/argoproj/argo-cd/blob/master/docs/ingress.md#option-1-ssl-passthrough

After reaching the UI the first time you can login with username: admin and the password will be the
name of the server pod. You can get the pod name by running:

kubectl get pods -n argocd -l app.kubernetes.io/name={{ include "argo-cd.name" . }}-server -o name | cut -d'/' -f 2