Hi @Sergio Augusto Pereira , Thanks for using Microsoft Q&A Platform.
Sorry to hear that you are experiencing this situation.
There could be several reasons for this:
To begin with, this error may occur if the custom domain endpoint you are using is incorrect, or if the resource you are attempting to access has been deleted or moved. Please double-check the following information, as mentioned in the document: https://learn.microsoft.com/en-us/azure/cognitive-services/translator/document-translation/quickstarts/get-started-with-rest-api?pivots=programming-language-csharp#your-custom-domain-name-and-key
Have you also followed the QuickStart document and configured the SAS token for storage containers.?https://learn.microsoft.com/en-us/azure/cognitive-services/translator/document-translation/quickstarts/get-started-with-rest-api?pivots=programming-language-csharp#required-authentication
Can you please try these and let me know if that helps? can you please share the complete Json error message?
Please kindly accept the answer if you feel helpful to support the community, thanks.
Regards,
Vasavi