When managing apps, if the admin clicks "+ Build a new app", Confluence throws a "Page Not Found"

Summary

When managing apps, if the admin clicks "+ Build a new app", Confluence throws a "Page Not Found"

Environment

Confluence Cloud

Steps to Reproduce

1. Log in as a Confluence admin;
2. Access the "Manage Apps" section;
3. Click + Build a new app;

Expected Results

Confluence opens the correct page for these functions.

Actual Results

Confluence throws a "Page Not Found" error instead.

Workaround

Customers can visit the page linked from "build a new app" directly by pasting this URL in the browser:

<site-name>/plugins/servlet/upm/develop?source=manage