installing alexa error

[tbs86]

hello. ive been trying to install alexa on my MM. but while running the command

cd javaclient && mvn exec:exec i get this

[INFO] Scanning for projects...
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.819 s
[INFO] Finished at: 2018-12-08T18:18:28-08:00
[INFO] Final Memory: 7M/17M
[INFO] ------------------------------------------------------------------------
[ERROR] Could not find goal '' in plugin org.codehaus.mojo:exec-maven-plugin:1.2.1 among available goals exec, java, help -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoNotFoundException

I am unsure what to do i have google this and have no answers. if you could help that would be great. thanks

[tbs86]

Anybody have any clues? I’m at a loss here