[CSM] minetest.localplayer is nil

[AFCM]

Hi,
I have tried to create a simple csm who send to the player a chat message when he connect.
But minetest.localplayer and core.localplayer are nil, so I can't get the player name.
It is very strange, because the default test csm work perfectly (and use core.localplayer)
minetest.localplayer is referenced in client_lua_api.txt
All csm restriction are disabled and I used minetest 5.3.0
Can everyone help me ?