How to use the efiling ITR UTILITY (JAVA) of Income Tax Department in Ubuntu 18.04 LTS?

For the purpose of efiling Income tax return, the IT department has provided a utility using Java( JRE Runtime Environment 8U51). I am not very experienced in installing and using java, though I have been using Ubuntu for the past few years. Presently I use Ubuntu 18.04 LTS. . I have installed the java software from the tutorial I got from ITSFOSS writeups that I got for my google searches. But I am unable to open and use the JAVA Utility after downloading from incometaxindiaefiling site. It would be very much helpful if anybody could help me in using this UTILITY