Use the plain bucket name only — e.g.

my-data-bucket

. No

s3://

prefix, no ARN, and no folder paths. - Need a subfolder? Put it in the block’s “bucket folder”/default path field (if shown) or include it in your object keys when you read/write (e.g.,

reports/2025/run.json

). - Using MinIO or another S3-compatible service? Still just the bucket name; set the custom

endpoint_url

(and credentials/region) in the block’s client settings. Refs: - Blocks overview - Storing credentials/secrets