docker run -d -p 8081:8081 -e ME_CONFIG_MONGODB_ADMINUSERNAME=admin -e ME_CONFIG_MONGODB_ADMINPASSWORD=password -e ME_CONFIG_BASICAUTH_USERNAME=myuser -e ME_CONFIG_BASICAUTH_PASSWORD=mypassword -e ME_CONFIG_MONGODB_SERVER=mongo --net mongo-network --name mongo-express mongo-express

yes above command works for me when I enter the basicauth username and password