Read, update, and delete Apple Messages for Business assets through the Digital Asset API (channel=applebusinesschat, channelId=23), and upload the brand/rich-link media and the ABC certificate/configuration file used to onboard the asset. Like some other Digital-Assets channels in this product group, Apple Messages for Business does not support the shared create operation (POST /v2/digital/app); the shared create operation remains available only for email, app, rcs, fb, and wa. Credential-bearing examples are sanitized for developer-portal publication.