Unable to add attachments on Manage NIR page while on Definition stage by Requester/Reviewers

Unable to add attachments on Manage NIR page while on Definition stage by Requester/Reviewers,

When a NIR is created for an Item by a Requester, it first goes to Level 1 reviewer as part of definition stage to review/edit any item details and if needed to add attachment on 'Manage NIR' page instead of notification page for the next reviewer to view the updates (which currently the reviewer is not able to) and same is the issue with Level 2 reviewer on NIR page. We want the ability of Requester/Reviewers to add attachments at Manage NIR page so that the history is managed and is visible to all reviewers to know to updates on