post https://api.trinsic.id/api/v1/attachments/attachment
Exchange an Attachment Access Key (from IdentityData.Attachments) for the raw contents of the attachment.
Use this API to fetch document (front, back, portrait) or other (selfie) images from a verification, if relevant.
In some cases, attachments may not be immediately available after a verification is completed.
If so, this endpoint will return an HTTP 503 code, and you should try again later.