Hi
In dialplan i can set veriable via
session:execute ("set",<do what i need>)
or 
session:setVariable (<varname>,<var value>)

In chat plan exists only "set" application but in can not bee executed via message (analog of session)
how to set variables here?

I tried to use api:chat({<variables setup>} proto|sender|receiver|message)
But it is does not work
I exepted because of chat function description but tried anywhay.