GridDB not working on AWS cloud

I have installed GridDB in Ubuntu 18.04 running on an AWS cloud instance following instructions given on their website

Also in my bin directory I have all the commands:

# cd bin/
# ls
gs_adduser  gs_joincluster   gs_passwd     gs_stat         gs_stopnode  util.py
gs_deluser  gs_leavecluster  gs_startnode  gs_stopcluster  log.py

But when I am starting my cluster using gs_startnode it shows an error:

# gs_startnode -u admin/admin -w
Traceback (most recent call last):
  File "/root/griddb/bin/gs_startnode", line 122, in <module> proc = subprocess.Popen(command, stdout=f, stderr=f)
  File "/usr/lib/python2.7/subprocess.py", line 394, in __init__errread, errwrite)
  File "/usr/lib/python2.7/subprocess.py", line 1047, in _execute_child raise child_exception
OSError: (Errno 2) No such file or directory

Can anyone please tell me how to solve this?