there is a nice blog by Horst Keller about the difference between the logon language and the text environment (sy-langu): https://blogs.sap.com/2017/01/13/logon-language-sy-langu-and-rfc/
Using the URL-Parameter (or HTTP header field) sap-language, I can set the logon language.
My question is: Is there any way to set the text environment (sy-langu) as well?
Background: I want to return texts in more languages, than logon languages are installed in the system.
Thanks and best regards,