: Add the ViaFabric mod to your Fabric mods folder. This mod allows a newer client to connect to older server versions like 1.8.x.
: A highly customizable open-source hacked client that has a dedicated, long-standing version for 1.8.9.
: The developers prioritize the latest stable releases (currently supporting versions like 1.21.x) rather than backporting to legacy versions like 1.8.9. How to Play on 1.8.9 Servers Using Meteor Meteor Client 1.8.9 Download
If you are looking to use Meteor's powerful utility features on 1.8.9 servers, you must use a compatibility layer or choose an alternative client designed specifically for that version. Why Meteor Client 1.8.9 Isn't Available
: The oldest archived version of Meteor Client starts at Minecraft 1.14.4 . : Add the ViaFabric mod to your Fabric mods folder
The primary reason for the lack of a 1.8.9 download is the technical architecture of the mod:
You can still use Meteor Client while playing on servers that run 1.8.9 (such as Hypixel) by using "version-tunneling" mods. This allows your modern Minecraft client to communicate with older server protocols. : The developers prioritize the latest stable releases
ManInMyVan/meteor-archive: A Meteor Client archive. - GitHub