Create submenu/list with direct external links

we’re running a platform offering FOSS cloud services on a the basis of solidary economic.

I’m looking for a way to place the direct links to the five login pages of the services itself (nextcloud, mattermost etc.) on the landing page. Preferably in the top menu area.

I’m thinking of a dropdown menu or a (decent) second row in the menu.

So far, I’ve not really found a promising solution and would love to get some hints/help on it.

thank you!