As explained in the introduction, we need to create 2 logon procedures for RD Web. One for RD Web Access and the other for RD Web Client. 

For RD Web Access, we must create a Web SSO logon procedure

Once the logon procedure has been created, you need to add logon steps into the newly created logon procedure.

As the logon procedure for RD Web Access is a Web SSO, you can add as many logon steps as you like. And, you can add any type of authentication method in every logon step.

Typically, you will add 2 logon steps.