I don't think there are any links to such a thing in discord. You might try to ask for an invite to the servers you would like to look at. There are several servers auditors and activists use including the Speakeasy, CRUD, and Blacklable's server.
This is an invite to the Speakeasy: Join the Merb's Speakeasy Discord Server!
This is an invite to CRUD: discord.gg/N22CkKa
This is an invite to Blacklable's discord: Join the WE THE PEOPLE Discord Server!
To use discord, you need to add the app for best results. Then set up an account...it needs an email address...then click on the invite. I don't know how long the invite links will last so let me know if these links fail you.