ConnectIQ Oxygen SpO2 level reading

The value is not exposed in CIQ.

Is it planned to add this value to CIQ in future? It is really important and useful parameter. 

Unknown at this point.  The next round of new future features have not been announced.  I expect this will probably get announced at the developer summit in October .

So any updates on this?

But it seems that Fenix 5x plus cannot display Oxigen saturation on a watchface, even if it is in supported devices.

Anybody knows why?

now you can get it from [Toybox.SensorHistory]

using Toybox.SensorHistory;
using Toybox.Lang;
using Toybox.System;

// Create a method to get the SensorHistoryIterator object
function getIterator() {
    // Check device for SensorHistory compatibility
    if ((Toybox has :SensorHistory) && (Toybox.SensorHistory has :getElevationHistory)) {
        return Toybox.SensorHistory.getElevationHistory({});
    }
    return null;
}

// Store the iterator info in a variable. The options are 'null' in
// this case so the entire available history is returned with the
// newest samples returned first.
var sensorIter = getIterator();

// Print out the next entry in the iterator
if (sensorIter != null) {
    System.println(sensorIter.next().data);
}

Have you tested this code on real device (especially you use elevation instead of oxygen history) and you are sure it run well? 

I've reported a bug but when and if it will be fixed, nobody knows...

forums.garmin.com/.../fenix-5-plus-x---no-spo2

yes, i did,on fenix 6 Pro,it worked

for f6 it run but problem is with f5X+