The right URL to access the file udploaded in Master Data is the following one:
https://{{accountName}}.vtexcommercestable.com.br/api/dataentities/{{acronym}}/documents/{{idWithouthAcronym}}/file/attachments/{{fileName}}
Pay attention to the {{idWithoutAcronym}} variable. When you upload a file to Master Data, it will generate a Registry Id with the format {{Acronym}}-{{randomId}}. For example: AC-af6e1fe9-95e7-11ed-83ab-02a7822e906g.
You’ll need to passonly the {{randomId}} part to the URL, without the acronym prefix. Example:
https://{{accountName}}.vtexcommercestable.com.br/api/dataentities/AC/documents/af6e1fe9-95e7-11ed-83ab-02a7822e906g/file/attachments/{{fileName}}.
That’s it. Don’t forget to select the field to be public in the Data Entity configuration.