Add users in basic authentication

Hello,

I installed my evaluate version of Power BI Report Server on a virtual machine, then I log in with admin account and upload reports where I have roles. I need to provide access to users outside my domain, so I want to use basic authentication (it's the best way, isn't it?) defining usernames and passwords.

I changed the RSReportServer.config file as explained at https://docs.microsoft.com/en-us/sql/reporting-services/security/configure-basic-authentication-on-the-report-server?view=sql-server-2017#main but now I don't know how to create new credentials and the only way I am able to connect is with my admin account.

I read many things about security and roles assignment but I have no user to associate to one of my roles.

Please help me. Thank you so much