Change your Declaration of Conformity to include the product's type/model and then upload a new, signed, version.

The Declaration of Conformity must contain something that uniquely helps it to identify your product. This means that the product's type/model, as you've entered it in the system, must be found in the Declaration of Conformity.

It's a basic requirement of a proper Declaration of Conformity and must be present in the document before the system will allow you to continue.