Plugins/s3 help - upload folders , not only files

I’m trying to use plugins/s3, but I’m wondering how do I manage to ALSO upload folders to my minio bucket?
this is what my drone.yml looks like:

kind: pipeline
name: default

   - name: upload
     image: plugins/s3
       bucket: bucket
       region: eu-west-1
       path_style: true
       access_key: xxx
       secret_key: xxx
       source: ./*
       target: ~/test

this works for files, but what do I have to fill in at Source to also upload the folder (With the files in it)?

what i have already tried:
source: ./*
source: /
source: *

the first 3 are failed and the last one says that the empty file cannot be found…

any suggestions?