Set an explanatory block on the hosted page. Each save replaces all of the account's blocks for that type, so send the full list (at least one). An image can be a URL, kept as is, or a base64 data:image/... URL, which is uploaded and replaced by its URL.

Prerequisites: a bearer token and the account's id (company_id).

Authentication: Partner or Account token. company_id must be inside your own account tree (a Partner token reaches any account under the partner, an Account token only its own); otherwise 422.

Rate limit: none.