Error while log in pulsar manager ui

Hi
We are trying to install pulsar on our test environnent to test for a production use. We install it by using helm chart. Looking to have a ui to administrate it we enable pulsar manager on the chart helm.
We got an 404 error while using the default user pulsar/pulsar. We don’t know what we are missing.

We test ssl and no ssl mode and got the same error (404). No logs in the pod! The error is an the navigator side
Have any idea about what we have missed ?
We only change replicas number for the cluster and enable manager. All other chart parameters still by default.

Regards