You can provide users access to the launch page either in a standalone Web browser or in SAP NetWeaver Business Client or SAP Enterprise Portal.
To provide users access to the launch page in a standalone Web browser, use the following URL:
https://<server>:<port>/sap/bc/ui5_ui5/ui2/launchpage/home.html
You can append URL parameters that start with sap-, for example, sap-client, sap-language, or sap-theme. These parameters are also passed to the applications that are launched from the launch page.
The login page automatically adds some parameters to the URL, like sap-language and sap-client.
To provide users access to the launch page in SAP NetWeaver Business Client or SAP Enterprise Portal, assign the users to the following standard role in PFCG:
Launch Page (SAP_UI2_LAUNCH_PAGE)