Sensuctl configure prompting error : Error: unable to authenticate with error: Unauthorized

I just install sensugo 5.19.1 on centos7. When i configure it it show follwing error.

[root@dev-box-c7 ~]# sensuctl configure
? Sensu Backend URL: http://127.0.0.1:8080
? Username: admin
? Password: *********
? Namespace: default
? Preferred output format: tabular
WARN[0011] Using Basic Auth in HTTP mode is not secure, use HTTPS component=cli-client

Error: unable to authenticate with error: Unauthorized

Since it’s a new install did you initialize the backend to set to configure the initial username and password?

https://docs.sensu.io/sensu-go/latest/installation/install-sensu/#3-initialize