Thanks for your reply i will try with CLI.
I tried running the code above but got the following output. Should I have placed the .deb file in a certain location before I run that command?
james@CNCPC:~$ sudo dpkg -i nomachine_8.16.1_1_amd64.deb
[sudo] password for james:
dpkg: error: cannot access archive ‘nomachine_8.16.1_1_amd64.deb’: No such file or directory