Summary
Currently, the API to create a sku file https://developers.vtex.com/docs/api-reference/catalog-api#post-/api/catalog/pvt/stockkeepingunit/-skuId-/file is not responding with the "Text" property correctly.
This field's data is accepted and sent to the database, however, the response body of any of the SKU file's methods (GET, PUT, POST) are always responding the JSON response body containing the "Text" property as null, even when it has a saved value in it.
Simulation
1 - Using the aforementioned API, send a request body for a valid image that has a "Text" field with a non-null data. 2 - Check either the response body of this API or use a GET request to fetch this file's data, the Text field will be null. 3 - However, if you go to the store's admin, in https://VTEX.myvtex.com/admin/Site/SkuForm.aspx?IdSku= you will see that the text displays the data from the sent field.
Workaround
Fetch data, for the Text field from the admin, spreadsheets or search APIs.