...

{
    urlProxy: "index.php",
    urlFramework: "js-i2b2/",
    startZoomed: true,
    lstDomains": [
        {
            domain: "i2b2demo",
            name: "HarvardDemo SAML",
            allowAnalysis: true,
            urlCellPM: "http://127.0.0.1/i2b2/services/PMService/",
            registrationMethod: "saml",
            loginType: "federated",
            showRegistration: true,
            installer: "/webclient/plugin_installer/",
            debug: true
        },      
        {
            domain: "i2b2demo",
            name: "HarvardDemo",
            allowAnalysis: true,
            urlCellPM: "http://127.0.0.1:9090/i2b2/services/PMService/",
            registrationMethod: "",
            loginType: "local",
            showRegistration: false,
            debug: true
        }
    ]
}

Optionally, you can follow these directions to customize the SAML IdP login button: 
i2b2 SAML: Customize Identity Provider (IdP) Login Button

Restart the Apache web server:
systemctl

...

restart

...

httpd.service

Updating the Lookup Table in the Database

...