Confirmed also on 3.4.0-dev (latest staging)
It is a 404...

<rant>Sorry, but I am not willing to register on a 3rd party SaaS ticketing system (atlassian.net) to report this. I really don't see the rationale behind this: we already have our ticketing system.</rant>

@smz The JED's workflow predates our issue tracker becoming the primary system for Joomla core and I'm not going to "highly suggest" they change their workflow to use our system.

Regarding the issue specifically, it's a work in progress right now. The plugin was pulling data against the old JED's database and the code is being updated for the new system.

@smz You don't have to register at their ticketing system because it's likely not an issue on their end.
But you need to open an issue in the proper repo on our end. That's either
https://github.com/joomla-extensions/install-from-web-client for the client or https://github.com/joomla-extensions/install-from-web-server for the server.

Closing this as not an issue of Joomla core.

@mbabker & @Bakual Thanks to both: got it!

@YGomiero
Here it is
joomla-extensions/install-from-web-client#8