It appears to generate 3 empty folders inside the config for the server Carvers/features/scripts
None of the generated folders contain a config file.
No place online I can get a config file.
How to start config file???

Using dw20 1.19 v1.1.1

The toml-file is inside the config folder and if you want to modify you need to create a config file yourself. You just need to safe it with ".cfg" at the end.

ok, but how do we make a cfg file? what do we need to put in it?

so, biometweaker does't need a second cfg file to point it to the script anymore?
Also, I noticed the commands didn't seem to mention villages. is it possible to tell it to allow a village type to spawn anywhere? or drastically reduce the number of trees that generate? I'm playing with a custom post-apocalyptic modpack and wanted to make the few vanilla biomes more wasteland like by reducing their tree spawns or chance of generating.

Either you use a text editor like Notepad++ or you use a software like Eclipse (which can be more confusing in the beginning). You can name the file whatever you want but you have to add a .cfg at the end of the name (it's somewhat of a script file) and put it inside of config/biometweaker/scripts. If you look at the wiki page Biometweaker 1.18) you can see all the possible commands.
You start by creating the output files ingame with the command /biometweaker output. Then you can find all the dimensions, biomes, features, carvers and entities in the output folder inside config/biomtweaker/output. You can only use these by default for custom features and carvers you need to create a json-file in the features or carvers folder (whatever you want to name it) and either copy a former feature/carver and modify it or recreate one on your own (a feature needs an additional file inside config folder there). If you copy it you only want to include every part that is inside the curly brackets after worldgen/[...]:. Be aware that you have to look up the min and max values (on minecraft wiki) as a wrong configured file will be ignored without giving any errors.
Then you can use the cfg-file to adress your biome with the help of the registry names inside the output folder like biome = forBiomes("minecraft:plains") or biomes = forAllBiomes("minecraft:plains", "minecraft:jungle") for multiple biomes at once (the name before the equals sign can be changed). Everything after that depends on what you want to do with the biome and be aware that you have to register your features with Tweaker.registerFeature("name") (name is the same as how you named the json-file) and your carver with Tweaker.registerCarver("name") before adding them with biome.addFeature("name") or biome.addCarver("name"). You should remove the older carvers before adding a new like biome.removeCarver("AIR", "minecraft:cave") (look into the biome file for information) if you want to prevent unwanted behaviour. For everything else you should check the wiki.

I know this response is a bit late but there was no TOML file being generated as to rename into a .cfg

I know this response is a bit late but there was no TOML file being generated as to rename into a .cfg

You don't rename the toml, you just create a file like with an Text-Editor (like Notepad++) saving it with .cfg at the end (which in most cases leads it to be registered as cfg-file) under [...]/config/biometweaker/scripts and you modify it accordingly to the wiki depending on what you're aiming for. You need to start the game once and you should probably as well run the command /biometweaker output once for generating the data for existing features, biomes, entities, dimensions and carvers (you don't need to modify them instead you do that in the cfg-script).

so, biometweaker does't need a second cfg file to point it to the script anymore? Also, I noticed the commands didn't seem to mention villages. is it possible to tell it to allow a village type to spawn anywhere? or drastically reduce the number of trees that generate? I'm playing with a custom post-apocalyptic modpack and wanted to make the few vanilla biomes more wasteland like by reducing their tree spawns or chance of generating.

The Scripts-Ordner is there for a reason, so not really. You can find all features in the output if you generate it, you only have to remove (removeFeature) them from the biomes (one by one because every tree type has it's own feature) and replacing them with modified features. The villages count as structure... as I see it these can't be modified by biometweaker (probably because they're not biome-specific).