The Sitecore Marketplace is going to or retired already for technical reasons. Sitecore has now the new Developer Portal (https://developers.sitecore.com) and marketplace for pre-built connectors and apps from Sitecore and its partners that extend Sitecore, and make weaving it into client's business easy, fast, and flexible.
Sitecore recommends GitHub as a great place to host your modules, and many other community members are already doing this. A lot of community members will have an associated blog article posted somewhere to explain/advertise the module. Make sure your README in your GitHub repo has the information needed for search engines to surface your module to people looking for it!
I think Sitecore added redirects for these marketplace modules and that's why it is redirecting to the product marketplace - https://www.sitecore.com/products/marketplace
It's a Hack but for now, you can run the URL by removing the
.aspx and can download the module or can navigate to the GitHub repo
from the page.
I hope Sitecore will create some kind of page with links to these modules and GitHub path before completely retiring The Sitecore Marketplace.
Ref - How to contribute on Sitecore Marketplace now?