ViaVersion add-ons
If you also want to allow clients older than the server itself, you can install the ViaBackwards mod. Install it just like you installed ViaVersion or ViaFabric.
There are also ViaRewind
(for very old versions pre-1.8.9) and
ViaAprilFools
(which supports clients from april fools versions). You probably
don't need to install them, but they're listed below in case.
https://modrinth.com/plugin/viabackwards
https://modrinth.com/plugin/viarewind
https://modrinth.com/plugin/viaaprilfools
It's important to note that these versions may depend on ViaVersion or ViaFabric being installed, so if you need any of the extensions, install the main ViaVersion too.
ViaBackwards
,ViaRewind
andViaAprilFools
support both ViaVersion and ViaFabric. If you're using ViaVersion (plugin-based server like Paper) put the addons in your server'splugins
folder. If you're using Fabric, you can put the addons in yourmods
folder.