embed-server --server-config=standalone-ha.xml --std-out=echo 
batch

/subsystem=keycloak-server/spi=avatar-storage/:add
/subsystem=keycloak-server/spi=avatar-storage/provider=avatar-storage-minio/:add(enabled=true, \
  properties={ \
    server-url => "${env.AVATARS_SERVER_URL}", \
    access-key => "${env.AVATARS_ACCESS_KEY}", \
    secret-key => "${env.AVATARS_SECRET_KEY}" \
})
/subsystem=keycloak-server/:write-attribute(name=providers,value=[ classpath:${jboss.home.dir}/providers/*, module:deployment.avatar-minio-extension-bundle ])

:reload

run-batch 
stop-embedded-server