How to inset the snippet in polarion.

Go to your application portal.

You can copy the snippet in the deployment tab.

POLARION 19.3 and older

Edit the file /opt/polarion/polarion/plugins/com.polarion.portal.jetspeed_<version>/webapps/jetspeed/index.jsp

POLARION 20.0 and newer

Edit the file /opt/polarion/polarion/plugins/com.polarion.alm.ui_<version>/webapp/authapp/index.jsp 

and put the snippet just before body at the end of the file.

(alternatively you can setup some filter on bundled apache)

REMEMBER: this snippet gets removed on every update of polarion (from any version to any version)