OPC UA Server Certificate, Authentication, Nodes|OPC UA Standard|Forum|OPC Foundation

Hi, I have downloaded the UA-.NETStandard-Samples-master project from OPCFoundation Github, and I'm trying to modify a server (to be specific, it's the Quickstart Application - Empty Server) and add some function in the UI (like set Username, Password, add nodes,...)

I also have some questions for those function:

• For the Authentication, what I'm doing is go to file "Quickstarts.EmptyServer.Config.xml", and there are some xml nodes like this:

<UserTokenPolicies>

     <ua:UserTokenPolicy>

                 <ua:TokenType>Anonymous_0</ua:TokenType>

     </ua:UserTokenPolicy>

     <ua:UserTokenPolicy>

                <ua:TokenType>UserName_1</ua:TokenType>

    </ua:UserTokenPolicy>

</UserTokenPolicies>

 If I want my server accepts only Username "123" with Password "456", what will the code above be like? I think I should delete the Anonymous_0, but I don't know how the Username_1 works, and how to encrypt the password.

• For the Certificate, if I go to folder "%CommonApplicationData%\OPC Foundation\pki\trusted", then move the Client certificate to folder "rejected", then the Client cannot connect to Server. So what I should do with Certificate tabs of my UI is to move the certificate file of each client between "trusted" and "rejected" folder, right?
• For managing nodes, I think there's a xml file in my project folder to initiate all nodes, right? However I cannot find it in the Quickstarts Empty Server. Can you point me that?