Help with transfering old world from services.minecraft-server

[maxstrb]

Hello, I am have an old server defined with the built in services.minecraft-server but I would like to switch to nix-minecraft. Which files should I copy from /var/lib/minecraft to the new /srv/minecraft/survival-main. I have been trying for a while (all files, just world, ...) and nothing seems to work. I would appreciate any help. Thanks in advance.

Here is my config:

old config:
services.minecraft-server = {
enable = true;
eula = true;
declarative = true;
serverProperties = {
difficulty = "hard";
server-port = 25565;
gamemode = "survival";
motd = "Nejaky server";
max-players = 10;
level-seed = "10292992";
white-list = true;
};
whitelist = {
jirka_ag = "19b738eb-8a61-40a3-80fd-7fd1cdec4f00";
DeathZone24 = "29dcb5e0-49b5-48ad-9981-ff6c4e0a5a7f";
ben_ag = "7626ac15-cbea-46e1-9c89-8b19b99fce86";
GamesAdam05 = "47410ae2-812c-4e78-b4b7-4147425e0940";
};
};

new one:
services.minecraft-servers = {
enable = true;
eula = true;
servers = {
survival-main = {
enable = true;
package = pkgs.vanillaServers.vanilla-1_21_8;
serverProperties = {
server-port = 25565;
difficulty = "hard";
gamemode = "survival";
motd = "Survival Server";
max-players = 10;
white-list = true;
level-name = "world";
level-seed = "10292992";
};
whitelist = {
jirka_ag = "19b738eb-8a61-40a3-80fd-7fd1cdec4f00";
DeathZone24 = "29dcb5e0-49b5-48ad-9981-ff6c4e0a5a7f";
ben_ag = "7626ac15-cbea-46e1-9c89-8b19b99fce86";
GamesAdam05 = "47410ae2-812c-4e78-b4b7-4147425e0940";
};
};
};
};