my start in datapacks HELP

I'm developing a datapack that generates a procedural dungeon using jigsaw and structure blocks. But the datapack can't find my structures.
Console error:
Failed to handle packet ahd@5e071ed6, suppressing error
java.lang.IllegalStateException: Missing element ResourceKey[minecraft:worldgen/template_pool / talon:couloir_1]
Here is my datapack structure:
talon/
├── pack.mcmeta
├── data/
│   ├── minecraft/
│   │   └── tags/
│   │       └── worldgen/
│   │           └── template_pool/
│   │               └── talon.json
│   └── talon/
│       ├── structures/
│       │   ├── couloir_1.nbt
│       │   ├── couloir_2.nbt
│       │   ├── tri_1.nbt
│       │   └── ... (other .nbt files)
│       └── worldgen/
│           └── template_pool/
│               └── pool.json
My .json files are valid.
The .nbt files are saved in the correct folder.
The namespace is consistent (talon).
/reload runs without issue, but the structures won't generate.
Using /place structure talon:couloir_1 also says the structure doesn't exist.
I'm a beginner, so if you have any idea what might be wrong, I'd appreciate any help.
(Sorry for my bad English, I'm French.)
PS : i try ai it havn't help me