i think OTA update available. if you're not able to find. then open smartswitch app in laptop/desktop, download the smart switch app in computer. Then open the app, now connect then phone via USB. the app notify the update. Its a full size update around 6GB. so you need highspeed internet to download. once its downloaded it will automatically updated your phone. you shouldn't touch your phone until the process complete and phone restart. Your phone must have atleast 80%battery.
