After you've uploaded your Declaration of Conformity, you will get to the agreement page.

Here, the system lists what documents you need to have in order to be represented. This is part of your documentation and is called a "technical file". 

Carefully review the required documents, ensure that you can have them available to us within 5 work days when requested.

If you click on an entry, you can see the exact legal references that require you to have these documents.

What if I don't have the documents?

You must have the documents for us to be able to represent you, it's part of the EU legal requirements. If you don't have the documents, or can't produce them within 5 workdays, you cannot be represented. If you sign the agreement either way, you would be in breach of the agreement and the whole agreement would be invalid.