Thank you very much:
It worked 
but I also had to change to docker command to:
(use ELASTIC_PASSWORD instead of ELASTICSEARCH_PASSWORD)
docker run -p 9200:9200 -p 9300:9300 -e "discovery.type=single-node" -e "ELASTIC_PASSWORD=black" -e "xpack.security.enabled=true" docker.elastic.co/elasticsearch/elasticsearch:7.12.0
also i did tried to play with ELASTICSEARCH_USERNAME and ELASTIC_USERNAME
but no result