CanUserLogin exists in Oxide:
https://umod.org/documentation/games/rust#canuserlogin
https://umod.org/documentation/games/universal#canuserlogin
https://github.com/OxideMod/Oxide.Rust/blob/614fd2fd10b90b50b22d23f98b6124ed49cb48ac/src/RustHooks.cs#L274
Yet it is marked as Carbon-only:
https://docs.carbonmod.gg/docs/core/hooks/player#canuserlogin
CanClientLogin exists in Oxide:
https://github.com/OxideMod/Oxide.Rust/blob/614fd2fd10b90b50b22d23f98b6124ed49cb48ac/src/RustHooks.cs#L273
Yet it is marked as Carbon-only:
https://docs.carbonmod.gg/docs/core/hooks/player#canclientlogin