How to stop a nohup process running rails server on port 3000

I have started a rails server puma by using the following command.

 nohup rails server &

its output was [2] 22481 along with the following:

nohup: ignoring input and appending output to 'nohup.out'

But now I have forget the returned process id, so how can I detect the process id so as to delete the process on aws.