Mark 1.21.1 as supported.
External resources
Project members
CharcoalWhite
Owner
Technical information
License
GPL-3.0-or-later
Client side
unsupported
Server side
required
Project ID
nineMinecraft is a joke site.
nineMinecraft is in no way affiliated with Modrinth or 9minecraft. (And frankly, who wants to be affiliated with the latter?)