Not possibleto login with username string outside the 0x00 to 0xFF range
The method btoa does not work with unicode string outside the range: https://developer.mozilla.org/en-US/docs/Web/API/WindowOrWorkerGlobalScope/btoa
This method is used to construct the Authorization session which contains the username.
We should use the solution to convert to ucs-2: https://developer.mozilla.org/en-US/docs/Web/API/WindowOrWorkerGlobalScope/btoa#Unicode_strings