Go the Translation overrider file
Enter the document name to be changed in the Id, and enter the Arabic and English names of this Id
In a new line, enter the same document name followed by (s) letter, and enter the Arabic and English name for the plural name of the document to be translated.
Save the record and Reload the translations.
You can know the document name to be translated from the link of this document.
For example, the sales invoice name will be the SalesInvoice word in the part “/0&entity/SalesInvoice&page”