Trying to call MavLinkInterface's InjectGPSData()

Ground Control Software Mission Planner
1

My goal is to programmatically update the UAV’s LLA coordinates with a function call. I found the function InjectGPSData and it seems it would do what I want. I could not figure out how to get this function to be called with the normal GUI so I could not get a breakpoint in to see what the byte[] is supposed to look like. Could someone explain what formatting this function is expecting? If this will not do what I want is there another function call or method to achieve direct control of the LLA of the UAV? Here is my code so far.

string mes = "lat = 50.46, lon = -91.01, Alt = 1000"; // Needs to be formatted correctly
byte[] data = Encoding.ASCII.GetBytes(mes);
foreach (var port in MainV2.Comports)
{
    foreach (var MAV in port.MAVlist)
    {
        port.InjectGpsData(MAV.sysid, MAV.compid, data, (ushort)data.Length, true);
    }
}

This code under MainV2.cs caught my eye.

if (cmds.ContainsKey("rtk"))
{
    var inject = new ConfigSerialInjectGPS();
    if (cmds["rtk"].ToLower().Contains("http"))
    {
        inject.CMB_serialport.Text = "NTRIP";
        var nt = new CommsNTRIP();
        ConfigSerialInjectGPS.comPort = nt;
        Task.Run(() =>
        {
            try
            {
                nt.Open(cmds["rtk"]);
                nt.lat = MainV2.comPort.MAV.cs.PlannedHomeLocation.Lat;
                nt.lng = MainV2.comPort.MAV.cs.PlannedHomeLocation.Lng;
                nt.alt = MainV2.comPort.MAV.cs.PlannedHomeLocation.Alt;
                this.BeginInvokeIfRequired(() => { inject.DoConnect(); });
            }
            catch (Exception ex)
            {
                this.BeginInvokeIfRequired(() => { CustomMessageBox.Show(ex.ToString()); });
            }
        });
    }
}