Hi team Can we change the default password for datahub ?

Hello Karishma, Yes, this depends on authentication method you configured DataHub with. By default it uses JAAS login which is a user/pass combo:

Pro-Tip: To login using the datahub account, simply navigate to <your-datahub-domain>/login and enter datahub, datahub. Note that the password can be customized for your deployment by changing the user.props file within the datahub-frontend module. Notice that JaaS authentication must be enabled.

Link: https://datahubproject.io/docs/policies/#managing-policies