Need help for keymap

[Bertrand]

Hello,

I installed a laptop on which I have encrypted all partitions (see https://blog.wycd.net/gentoo-setup-fde-lvm-genkernel/)

When Grub launches:
   - He asks me my key to unlock the encrypted disk
   - if password is ok, I can choose the kernel to boot

Unfortunately, when I type the password, the keyboard is Qwerty. I would like it to be in be-latin1.
I tried to create a "/etc/grub.d/50_custom" file that contains:
#!/bin/sh
insmod keylayouts
keymap /boot/grub-layouts/be-latin1.gkb

I try to generate the configuration Grub:
# grub2-mkconfig -o /boot/grub/grub.cfg
Generating grub configuration file ...
Found linux image: /boot/kernel-genkernel-x86_64-4.0.5-gentoo
Found initrd image: /boot/initramfs-genkernel-x86_64-4.0.5-gentoo
insmod: ERROR: could not load module keylayouts: No such file or directory
/etc/grub.d/50_keyboard: line 2: keymap: command not found

The file '/boot/grub-layouts/be-latin1.gkb' exists :
# ls -l /boot/grub-layouts/be-latin1.gkb
-rw-r--r-- 1 root root 2572 Oct  6 08:43 /boot/grub-layouts/be-latin1.gkb

The module keylayouts' also exists:
# locate keylayouts
/boot/grub/i386-pc/keylayouts.mod
/usr/lib64/grub/i386-pc/keylayouts.mod
/usr/lib64/grub/i386-pc/keylayouts.module

Does anyone know what the problem is ?

I thank you.

Kind regards,

Bertrand