Complete XMR node

What is required to add monero node to make freedombox the i2p + monero equivalent of an umbrel? I believe this would bring in the monero community and further the future development of freedombox.

Could you more specify your question? What do you mean by “what is required”?

How do I install full XMR gui and node on freedombox?

I suppose you mean how to implement a XMR node as a Freedombox App? I haven’t looked into the prerequisites for it but as I understand it it all Freedombox Apps rely on the Debian repositories and therefore need to be installable with an apt command.