The "Client Trust File Path" is the absolute location on the Jenkins server to the client trust file. This trust file is generated by the command line on the Liberty server (see documentation). This file should be copied to the Jenkins server and its path specified in this input field. Be sure to use an absolute path! If WebSphere Liberty is located on a remote server, the self signed certificate provided by the Liberty server should be imported into your trust store for the JRE that's running Jenkins (again see documentation).