Options for S3Provider (and 'b2' preset).
optional
region: string
AWS region.
bucket: string
Bucket name.
optional
accessKeyId: string
AWS access key ID.
optional
secretAccessKey: string
AWS secret access key.
optional
endpoint: string
Custom S3-compatible endpoint (R2, MinIO, B2).
optional
client: IS3Backend
An implementation of the S3 backend, bypassing the lazy SDK import.
This is NOT a place to put an @aws-sdk/client-s3 S3Client; see
IS3Backend. Injecting a real SDK client is refused at
connect() with the methods it lacks.