speed move

[TimRou4]

Hello! I encountered a problem when I use the configuration to strengthen zombies in the special folder.
I didn't write it at all, and the code was copied completely from the wiki of this mod.

[
{
"mob": "minecraft:zombie",
"result": "default",
"healthmultiply": 2,
"nbt": {
"Attributes": [
{
"Base": 0.23,
"Modifiers": [
{
"Operation": 10,
"Amount": -5,
"Name": "effect.moveSlowdown 0"
}
],
"Name": "generic.movementSpeed"
}
]
}
}
]

I wanted to reduce the speed of the zombies, but apparently something is wrong.