EPA has released a total of 4 out of 7 planned training modules here for the Chemical Data Reporting (CDR, formerly IUR) rule.
The fourth module tells you how to register for CDX - the online reporting tool - for CDR. Each individual who will be filing information on a chemical for a company must be registered. There is one authorizing official who signs the completed form and certification, but there can be multiple support registrants who actually fill in the form. If you are already a CDX user, you need to "add a program": Submissions for Chemical Safety and Pesticide Programs (CSPP)
The fifth module is on the electronic tool and actually using it and will publish in January.
Intriguingly, Module 7 is on Byproduct Chemical Substances. I can't wait!
EHS Strategies, Inc. can help you with CDR.