Easier to answer this way:
DISCOURSE_USE_S3: true
DISCOURSE_S3_REGION: eu-north-1
DISCOURSE_S3_ACCESS_KEY_ID: <something>
DISCOURSE_S3_SECRET_ACCESS_KEY: <something>
DISCOURSE_S3_CDN_URL: https://cdnfoorumi.katiska.eu
DISCOURSE_S3_BUCKET: <something>
DISCOURSE_S3_BACKUP_BUCKET: <something>
DISCOURSE_BACKUP_LOCATION: s3
S3_ORIGIN_ASSETS: https://foorumi.katiska.eu
Mine is one man, one admin operation. So I don’t need anything fancy, but easiness has high value.