how get response parameters

Try this irule:

when HTTP_RESPONSE {

   Trigger collection for up to 1MB of data
  if {[HTTP::header exists "Content-Length"] && [HTTP::header "Content-Length"] <= 1048576}{
    set content_length [HTTP::header "Content-Length"]
  } else {
      set content_length 1048576
  }
   Check if $content_length is not set to 0
  if { ([HTTP::status] == 200) && ($content_length > 0)} {
    HTTP::collect $content_length
  }
}

when HTTP_RESPONSE_DATA {
     do stuff with the payload
    find the application unique identifier between  and  (5 is the length of  string)
    persist add uie [string trim [findstr [HTTP::payload] "" 5 ""]]
}

when HTTP_REQUEST {
    persist uie [string trim [findstr [HTTP::payload] "" 5 ""]]

}