Lua script using MAVLink binding

Very new to the ArduPIlot ecosystem, climbing the learning curve. We have our own GCS and I am trying to get the Lua script below working from the mavlink library / binding. I am using copter 4.4.0 BETA-3 and within the release notes it seems to indicate that Mavlink may be included but I am not sure if that also means for Lua scripting. The ‘gcs_sent_text(…)’ works fine but any of the
commented out variants of ‘mavlink:recv_chan()’ issues an error in MP messages as:

function update () – periodic function that will be called
** – local msg, chan = mavlink:receive_chan()**
** – local msg, chan = mavlink.receive_chan()**
** – local msg, chan = receive_chan()**
** gcs:send_text(4, “Hello world!”) – send the traditional message**

** return update, 1000 – request “update” to be rerun again 1000 milliseconds (1 second) from now**
end

return update, 1000 – request “update” to be the first time 1000 milliseconds (1 second) after script is loaded

Is Lua support for the MavLink library / binding baked into ArduPilot v4.4.0 BETA-3?

Regards,
Steve Bosse