IBM Cloud Object Storage Creds for s3cmd [closed]

I want to use s3cmd with IBM S3 API, but it looks like I can't find proper access_key, secret_key and corresponding host_* params for my .s3cfg.

What I do:

1. in IBM Cloud portal I open 'Manage > Access (AIM) > Service IDs' (https://cloud.ibm.com/iam/serviceids)
2. 'Create (+)' button to create new ID, it looks like ServiceId-...-f5186a3e81f0. I don't change 'Access group' and 'Access policies', is it correct?
3. in 'API keys' with 'Create (+)' button I make new record and copy received key to .s3cfg

Then I iterate endpoints in documentation to guess suitable one, but my s2cmd --configure still says me

ERROR: Test failed: 403 (InvalidAccessKeyId)...

I honestly tried to fond "Quick start" tonight, but I forced to ask your help here.

Can you please point me to brief howto or say, what I make incorrect.