Since Haven & Hearth it's client is open source, there are a couple of public available client modifications.
It always requires you to have the full modified client, since there is no modding api to enhance the default one.
Or you can just use the default one, if you don't like putting your faith in 3rd party clients.
You'll need to have Java installed to run the game. I'd suggest you install
OpenJDK.
Although it is technically the "development kit", it's pretty easy to install and use.
The steam version of the game comes with OpenJDK version 21.
Default Client
There's not much to say other than, it's the default. It does it's job.
Ender Client
Available since 2015, currently the most used custom client, for a good reason.
It brings a ton of extra QoL features to the table.
If you don't have any specific needs, this one is problably your go-to client.
Ard Client (by Cediner / Naylok)
It's history is a bit longer and more complicated. This client is still using an old rendering implementation of the original client
But it's got a couple of extra features that are nowhere else to be found yet.
The current maintainer is working on a 'successor' called beyond. If that goes life, I'll replace it, since it probably will mean the death of the ArdClient.
Kami Client
Originally planned as a continuation of Ender Client, when he announced he would retire, Kami Client was created to fill a gap.
Luckily for the community, Ender quickly came back and is still maintaining his client.
So basically Kami Client is based off on Ender, with some minor changes.
It has a windows based updater with supplied jdk for the client, so there's no need for you to install the correct java version.