Webpagetest Server behind Reverse Proxy Sub path

Hello,
I am attempting to put the server behind a reverse proxy sub path as www.xyz.com/webpagetest. I am doing this on k8s, and using traefik for the reverse proxy. Tried few things like setting cdn=webpagetest/ in settings.ini but no help.

Ingress:

---
kind: Ingress
apiVersion: extensions/v1beta1
metadata:
  name: ingress-wpts
  annotations:
    kubernetes.io/ingress.class: traefik
    traefik.frontend.entryPoints: http
    traefik.frontend.rule.type: PathPrefixStrip
spec:
  rules:
  - http:
      paths:
      - path: "/webpagetest"
        backend:
          serviceName: wpts-webpagetest-server
          servicePort: 80

I wanted to know if webpagetest supports something like setting root url for the website.

Any leads will be helpful. Thanks.

Regards,
Shobhit Sharma