Encoding xls file when requesting rails?

Question

Ruby on Rails

There is an xls file generation, it works correctly, when accessed from the browser, the file is downloaded and displayed in excel with the correct encoding, so if I make a request through the HTTP client, I also get the correct Russian text. I need to attach this file to a letter, I make a request using ActionDispatch::Integration::RequestHelpers
session.get('issues#index', {format: :xls,})
and as a result, question marks instead of Russian text in session.response.body. and

encode("UTF-8", :invalid => :replace, :undef => :replace, :replace => "")

doesn't help, it just doesn't change anything.
What could be the reason? Or can someone tell me another way to make an attachment in which I will not encounter such a problem?

Answer 1

I found a solution myself, in the request you need to specify Accept-Language: ru-RU
final request:

session.get('issues#index', {format: :xls}, {'HTTP_ACCEPT_LANGUAGE' => 'ru-RU'})