I started a blank 1.16.4 client with only The Lost Cities installed. I chose the "wasteland" preset but biomes were default. I tried to change the "allowedBiomeFactors" but it didn't help

More info please!

1. Version
2. to what values did you set allowedBiomeFactors?

1.16-4.0.5-alpha I didn't change configs at first. I just installed the mod in curseforge app, then started new world with wasteland preset but biomes were default. Then I opened config/lostcities/profiles/wasteland.json and changed allowedBiomeFactors from [
"desert=1",
"desert_hills=1",
"stone_beach=1",
"dead_forest=1",
"gravel_beach=1",
"outback=1",
"volcanic_island=1",
"wasteland=.3"
]
to
[
"desert=1"
]
and started new world again but nothing changed

You need to update to the latest version (and also to 1.16.5). The version you are using is buggy

Ok, thank you