https://wiki.archlinux.org/title/List_of_applications/Internet#Pastebin_services
That pages shows how to use curl to upload to 0x0.st.
I’ve used the pastebinit program listed on that page to upload to paste.debian.net, but it supports other sites as well.
No, I think if you’re using the nextcloud all in one image, then the management image connects to the docker socket and deploys nextcloud using that. The you could be able to update nextcloud via the web ui.
https://github.com/nextcloud/all-in-one?tab=readme-ov-file#how-to-update-the-containers