Hello back,
After some script reading, baikal now uses 256sha passwords.
echo -n admin:BaikalDAV:your_new_password| sha256sum | cut -d ' ' -f 1
Then replace the last line of /var/www/baikal/Specific/config.php with the new hash, same in /var/www/baikal/config/baikal.yaml and change the ynh config using yunohost app setting baikal password_hash -v your_new_hash
It worked without reloading any service.
Léo