Question(s)

[Fireworkstars46]

Is there a discord?

[EtlamGit]

No, but if you have questions you can use the Issues here.

[Fireworkstars46]

For the latest one (2.21.0), does it work on any MC version or only 1.21?

[EtlamGit]

It should work for any official Java based version, it is intended to be backwards compatible.
But I never tested early alpha or beta versions.

If you find a version that is not working, file a bug ticket.

[Fireworkstars46]

Like the version specifically is 1.6.4 or 1.12.2. But also another thing I want to know is if this tool would work on any modded biome like 7 days to mine (7dtm or BOP). And besides the biome, also want to know if it would not require a server or mod. Like my world is single player that's non server and modded biomes and want to make sure it acts like chunk base biome finder that a website or something or like amidst that uses my worlds level.dat file and shows any biome (even modded ones).

[EtlamGit]

Versions 1.6.4 and 1.12.2 are very old but should still work. There is really much changed in storage format, so I expect some problems. But just test it and if you experience bugs, make a bug ticket. Best would be to also upload a small test world.

Any modded Biome or Block will work as long as you provide a matching definition file. Someone has to define what color a Biome or Block shall render in and also other stuff as Mob spawn conditions and colors for leaves and water. There are some guides in the definition folder. It can be as simple as just a JSON file with a list of all Biomes. Also AMIDST does not know the correct color for your mod.

Minutor is completely server less, you even do not need Minecraft. Just the world storage folder (your save game)

[Fireworkstars46]

Also for the map itself, does it not show the whole world? Cause when I load it it only shows the ones I currently discovered in game.

[EtlamGit]

Yes exactly. Minutor shows your world. So everything that is in your save game folder. If you have not explored an area, this area is not existent (neither for Minecraft nor for Minutor). It is an offline map viewer.

In contrast AMIDST or Chunkbase show the Biome for a given world seed. They will never show your buildings or any other personal modification you have done to your world. If only theoretical Biome distribution is your interest, you might also test Cubiomes-Viewer.

[Fireworkstars46]

So I can't view my full world without discovering it?

[EtlamGit]

Not in the way you expect.

Your personal world does simply not exist until you discover it. Just imagine you are starting your singe player world with Minecraft 1.6, play some month then do an update to 1.7, play, update ... until today. During that time Minecraft has completely changed with new Biomes, new Structures and other stuff. So your world is a mix of different versions.
How should an external tool know what part of the world you discovered with what version of Minecraft?

In case you are interested in: "how your world would look in case you discover it with a specific Minecraft version"
you could use my tool SeePreloader to let Minecraft generate parts of your world.

[Fireworkstars46]

Is there other sites or tools like this one that would have that option?

[EtlamGit]

Like which tool? (Minutor, SeepPreloader or something else)

Your fundamental problem (personal/individual world only exists when discovered) is not solvable for any tool. It is simply not possible to show data that is not existent. You have to generate that data first. Chunkbase/AMIDST do that for Biome data only and are therefore very fast but only have Biome. If you want to see more, you have to generate full data, which is very slow and need much storage space.

To pre-generate Chunks in Minecraft, there are several tools (e.g. SeedPreloader).
Even in game Mods exists that teleport you around for several hours.

[Fireworkstars46]

I ended up using Amidst with the amidst mod in game and with it I can see modded biomes on amidst