Generally, the Server URL must contain the database name as it will be used for authentication purposes.
In cases where I am not able to login to Data Catalog as expected (which can be due to incomplete/incorrect Server URL), I would use the Local-based authentication and then modify the Server Configuration with the right values.
To use the Local-based authentication, a URL like below can be used:
After providing the password for the admin user ("admin", by default), I would be able to perform the changes related to the Servers as required.
You could take a look at the [Authentication and Authorization](https://community.denodo.com/docs/html/browse/latest/vdp/data_catalog/authentication_and_authorization/authentication_and_authorization) section under the Data Catalog Guide for more details.
Further, if I would like to add more servers in Data Catalog, I would click on the '+' button in the "Administration > Set-Up > Server > [**Configure the Virtual DataPort Servers**](https://community.denodo.com/docs/html/browse/latest/vdp/data_catalog/administration/servers_configuration/servers_configuration#configure-the-virtual-dataport-servers)" section of Data Catalog.
Hope this helps!