user-sso-registration-form in a modal

We are trying to open the Create username component on the community in a popup. From the documentation, we have created following:

<@modal id="user-sso-registration-form" label="custom.username.modal" />

The popup does open but the user-sso-registration-form is not rendering inside that. There is no error. Can we not use this module in the modal? Or are we missing some steps?