This is likely due to the Operator not having requested any document uploads when creating the E-sign/Document Request. 

If your consumer doesn't have the Upload Documents button/module available for them to click through and upload their documentation, you simply need add Request Uploads via the Consumer's Profile. Login to the Dashboard, click on Consumers tab, find the corresponding consumer that needs additional uploads and click through to their profile. 

Next you click on View & Request More, and click through their last request. This takes you to that Consumer's Document Requests page where you will click the Request More button. 

Assuming you had already requested all the correct documents for the Consumer to sign off on, there is no need to mark any of the check boxes to request new forms. Thus, you simply click the Continue button to get to the Request Uploads feature. Here is where you will enable the Upload Documents module for the Consumer by clicking the "Add documents to this request" button and selecting any of the corresponding options. 

Once completed, your consumer should be able to refresh the page, or log back in to the Consumer Portal and see that the Upload Documents module is now enabled and available for them to use.