The web-server running in Docker is checking the folder permissions, which has nothing to do with windows. In order to fix this you need to verify the folder permissions inside Docker itself
Below is an example , you just need to let docker execute the Linux command in a container
$ docker container exec -t local-container ls -ld /var/www/html/config
$ docker container exec -t local-container chmod 0770 /var/www/html/config