Ok, if you've setup the config file and Requester as per the blog, when you submit in Dynamics GP whatever you setup the requester for, do you see anything written into the eConnect_Out table?
Once the record(s) get written into the eConnect_Out table, it then should be picked up by the eConnect Outgoing Service, which then sends it to the MSMQ queue.
If nothing is being added to the eConnect_Out table, then either your config file and/or Requester is not setup and working correctly.
If the eConnect_Out table is being populated, but not making it to the MSMQ queue, then it's most likely the service not picking up the table contents.
**NOTE: If you're on GP 2015 or GP 2016, there is a documented issue where you'll need to install the GP 2013 Incoming and Outgoing Services for eConnect. This issue was fixed in GP 2018.
Thanks