Adding or Updating Asset Attachments in Maintenance Super User responsibility (HTML/Self Service)

Our company has a requirement to attach drawings, text notes and comments to EAM Assets.

We can do this in Forms, however, the majority of our users who are using HTML/Self-Service (through the Maintenance Super User responsibility) only have access to view Asset attachments.

When a user views the asset attachment in HTML, the "Update" icon can be seen, however, the tool-tip indicates the update functionality is disabled.  I cannot find any documentation to advise whether this can be re-enabled through a grant or a profile option etc

The Asset attachment functionality is very important to us, can anyone advise if allows Add or Update in HTML?