Hi @AlwynWong, thanks for reaching out with this question.
Once Custom Content with “space” container type is registered on the site the link to view a list of this custom content appears on the sidebar. There is no way to hide it by default, only space admins can do this with the “Edit space apps” dialog.
However, we are currently preparing to release custom content with Forge. And by default, custom content registered with Forge won’t show a link in the sidebar.
@ademoss For Custom Content registered with Connect we have a logic that automatically creates a WebLink in the sidebar. We don’t change it as it would be a breaking change and have a different user experience.
For Forge, we give this option to a developer and they can create a new confluence:spacePagemodule for this purpose.