Hi Henrik, thanks for your response!
I still cannot understand how to use this property. The following issues were found:
1). When I try to use load the body from file which has UTF-8 or UTF-16 format - the excess symbols in the start of the body appears independently on Encoding property value (I tried UTF-8, UTF-16, no value).
2). When I set the Encoding to UTF-16 & use the body loaded from file of any format - I can see the mass of unreadable characters instead of my body in the request - RAW tab. Of course service I try to push this request returns 400 saying the body is bad.
Could you please advice me how to use it correctly?