Interesting, because it shows up in the Connect app for me, at the top of the Activity Tracking page. Maybe reset your device?
This worked for me. Right after you reset and reconnect it, a pop up will appear, to set 4 things, among which is pulse ox. I remember that it showed up the first time too, but I probably snoozed it. After…
I could not find it on the Android app but when I logged into Garmin Connect on my computer I could see a greyed out slider after I selected the vivosmart 4 device and then the activity tracking heading.
When I tried to change it I got a popup that said I had to set the vivosmart 4 as my preferred tracker.
I only want to use it at night as I use a Fenix 5 during the day (too big for sleeping).
I have the Fenix 5 set as preferred.
This worked for me. Right after you reset and reconnect it, a pop up will appear, to set 4 things, among which is pulse ox. I remember that it showed up the first time too, but I probably snoozed it. After you enable pulse ox from there, it will appear in the activity tracking tab.
It's just a bug, reset the device and repeat the setup. The data will be saved on the app anyway.
My Gamin Connect App loaded into Samsung S8+ also was missing the Pulse Ox tab in Activity Tracking.
I uninstalled and resinstalled the Garmin Connect App...no change.
I had the Vivosmart 4 reset, then reconnect with the Garmin Connect App and went through the setup on the vivosmart in 4 steps. Nowhere did I see any setup choice for the Pulse Ox during the setup on the vivosmart.
Need some help from Garmin tech support. Otherwise I have to return the vivosmart I just got today.....
I finally got the pulse ox tracking for sleeping turned on in Garmin Connect.
Not sure which step I did corrected it.
I connected the tracker to the Garmin Express app that I installed into my PC, established the Vivosmart 4 tracker in that software. Then in Garmin Express, I looked into the tracker settings (Garmin Express then directs me to Garmin Connect). Found the pulse ox tab under Activity Tracking, turned it on for sleep and then PUSHED the SAVE tab at the bottom. All these settings are apparently saved online in my Garmin Account for the Vivosmart 4.
On my phone's Garmin Connect App, I deleted the Vivosmart 4 device that I had set up from the previous setup .
I reset the tracker again, then connected it via BT to the phone.
Then I pushed ADD DEVICE tab in the Garmin Connect App. The App searched and found the Vivosmart 4 tracker. Then on the phone it started going through a series of setup steps, including syncing, with the final 4 steps including setup of pulse ox.
The route I took may be contorted; but it worked!