So this is not a solution to the problem. If you are using Airtable and are AUTHORING these documents (I am), to have to render them to a public URL in order to have Airtable copy the content is a bit ridiculous. You should enable the ability to provide the document as a part of the create, or, perhaps enable a:
const id = ...stageAttachment(content);
const res = await base(table).create({ ..., attachmentId: id});
if you don't want to support that in the create.