Thanks Ines.
I was able to get this to work. There was a problem with the ec2 instance and fixed it now.
However, I have one last pressing issue. As I have mentioned earlier I am annotating for multi-label, multi-class classification task. I have around 100 classes, I want to start three parallel annotation sessions.
PRODIGY_PORT=5678 nohup prodigy [....] --label class1
PRODIGY_PORT=1234 nohup prodigy [....] --label class2 and so-on.
I am hosting prodigy application in Ec2 instance and able to run multiple sessions successfully. But when I use proxy_pass the external link says "Oops, something went wrong" - Project couldn't be fetched properly.
I tried proxypass with other generic websites and it works fine, so I am assuming it's got something to do with my prodigy project.