Mendix is app centric. So you have a node with environments where your app is running. Make sure that your app has the feedback button for the right user roles. Depending on the app I would not advise to give everyone access to the feedback button or your first line will be overwhelmed with feedback.
Make sure you have a person or persons whoes task it is to handle the feedback. They are the persons that should decide wheter something is a bug, feature wish or just a user question that directly can be answered.
Then somebody should evaluate the accepted feedback. What will be the priority. In which sprint will this user story go. Does it go on the backlog? How long is each sprint? When will be the next release? And with high enough priority it even could become a in between hotfix of your app.
The only way to handle the communication between business and IT is to define key users in business and make sure that they get informed about the decision about the sprints.
Most of these points you will also need to do if you are not using Mendix. The advantage of the tools is that you can gather all the feedback in one place and that the feedback can be transformed in user stories and sprint and eventually a new release.
Regards,
Ronald