Get User To Click The Feedback Button

We have an application (service) where most of our users are not the direct customer. Most of the users are contractors performing data entry and analysis using our software.

We don't have direct access to most users and due to the nature of the analysis it is not appropriate for us to contact a contractor. We can't observe as we can't see the data they are looking at as they may access confidential information.

We put a feedback button on the top menu but no one is clicking it.

They clearly know how to use the menu as that is how they get to most features. Users would only see Ver 3.10 (other number are only for dev cycles).

The button has been out there for months with hundreds of users and no one has left any feedback. The feedback page is just a simple select new feature or enhance existing, text box for input, and a submit button. I don't want to post that page as it has our support phone number.

How can we encourage use of the Feedback button without being obtrusive?

Is another word better?
Thought about "Request" but if they are just plain frustrated we want that feedback too. On the main menu we want to keep every item to one word.

Do you think they are afraid that feedback might get them in trouble?
We track who submitted but don't display it - if the customer asked us who we would tell them as it is customer data in a way.

We have some customers state contractors are "frustrated" but they don't give us specifics. Another dynamic is some of the contract firms have a competing product and they will complain to try and get us out. We track productivity and low producing users will sometimes say to the paying customer that the product is hard to use but not give specifics. If they have real complaints we want to hear them.

Here is what I used (for now) and put a click tracker on it