Hmmm.

Did some research and there's no way to straight forwardly have Discord delegate user management to an IdP.

This is in contrast that with other tools like Zendesk which let you do this pretty easily.

Of course, you can go the other way (have users log in with Discord) but that's not what you are asking.

There are some workarounds, but they require custom discord development. Here are some options:

Create a discord application that adds users to a server based on the oauth2 flow with the guilds.join scope. set that application up in a way that people need to sign in with FusionAuth and link that signup to their discord account. Your discord app that handles said oauth2 flow. Then you add users through that app instead of invite links. Use a public server but lock channels behind a role which gets added upon authorizing with FusionAuth by your bot. You could also use linked roles with a general access role people can opt into, if they fulfil the requirements set by that role (which you could control via registration at FusionAuth).

There's lots of documentation on creating discord bots but I don't have a specific example of any of these solutions, sorry.

With advanced threat detection you can block access to applications via IP ranges (it's touched on briefly here: https://youtu.be/pjGxOXamVfk?t=1209 ).

Advanced threat detection requires an enterprise license. Currently you can't lock a certain user to an IP range, though.

Please feel free to file a feature request with details of this use case if you'd like to see this implemented.