thanks Cumbu from stackoverflow.com!

‘public’ is valid policy…

You can change this policy: install mc (minio client) and then:

# list default hosts after install: 
mc config host ls

# remove all hosts: mc config host rm {hostName}
mc config host rm local

# add your host: mc config host add {hostName} {url} {apiKey} {apiSecret}
mc config host add local http://127.0.0.1:9000 ClientIdASSDSD ClientSecretASASASdsasdasdasdasd

# create bucket: mc mb {host}/{bucket}
mc mb local/mybucket

# change bucket policy: mc policy {policy} {host}/{bucket}
mc policy public local/mybucket