How to record calls on Apple iPhone XS Max ?

To turn ON LED Flash Notifications:Go to Settings > General > Accessibility > LED Flash > On.You can see detailed specifications here: Apple iPhone XS Max

To set an MP3 file for use as custom ringtone system-wide, do the following:Copy the MP3 files to your phone.Go to Settings > Sound > Device ringtone.Tap the Add button to launch the media manager app.You will see a list of music files stored on your phone. Your selected MP3 track will now be your custom ringtone.You can check the full specs here: Apple iPhone XS Max

You don't need to enable VoLTE. Insert the Jio (VoLTE enabled) in any slot. By default, VoLTE will be active. If it is not, you can change the network preferences from Network option in settings.Tap Settings > More.Tap Cellular networks > IMS Settings > Voice over LTE On/ Off.You can find full specifications here: Apple iPhone XS Max

You can follow the below mentioned steps to save battery:1. Turn off notification from less used apps:Real notifications are handy in some cases like email. But there is plenty of less important app that wants notification permission. Turn off those notification permissions. To do this Go to settings> Notification and status bar> App preferences. Choose and set important push message such as WhatsApp, what are enabled and disable other apps which you don't use often.2. Turn off GPS:GPS is another battery draining cause. Many apps request location permission using GPS. Turn it off to save your battery. You can use Wi-Fi-based location rather than GPS3. Enable battery saver in Security app:In MIUI 8 security apps comes with lots of feature including battery saver. Enable battery saver in security saver to get ultimate battery experiences.4. Set/Adjust Screen Brightness:Automatic Brightness: It is a good choice for adjusting screen brightness. But setting a constant brightness also save battery life. To set constant brightness Personally I prefer constant brightness and you can access them in Settings> Display> Brightness level.5. Turn off vibration on press:Every time you press on phone display it makes vibration. It is obviously power consuming. Turn off vibration on press to prolong battery life6. Turn off Wi-Fi:Turn off Wi-Fi when not needed. It is not mandatory to turn on Wi-Fi 24/7. It consumes huge battery.7. Turn off Sync:Syncing is also drained battery. Though it is important for apps like email but turn it off when not needed. You can turn in off in Settings>Sync.8. Turn off excessive vibration:Vibration kills your battery life. Try to avoid vibration mode. For app notification, you can turn it off in Settings> Notification and status bar> App notification> Choose only apps you want them to vibrate.9. Turn off auto update:Apps like Google Play store and app store constantly connect to the server to check for the updated app. This process drains battery fast. Turn off auto update to prolong battery life10. Shorten Screen Timeout time:Screen consumes huge battery. You can save some charge by shortening screen timeout time. Head towards Settings> Lock screen and password> Sleep and choose the time you prefer11. Use static wallpaper instead of live wallpaper:You can save some battery by shortening Use static wallpaper instead of live wallpaper Try to avoid live wallpapers.12. Turn on Airplane Mode in low signal areas:Phone consumes most battery in week signal area. So, turn on airplane mode when the signal is too poor.13. Keep phone updated:Updated ROM comes with optimization and bug fixes. So, keep your phone updated to prolong battery life.14. Turn on Power saver mode:You can simply swipe the notification bar and turn on the battery saver mode so that the battery usage is optimized.You can see full specifications here: Apple iPhone XS Max

Yes, iPhone XS Max supports OTG. USB OTG or USB On-The-Go is one of the most recent technologies that allows you to connect your pen drives and in some cases hard disks to your smartphones and tablets. It has a cable and through that cable, you can directly view and use your pen drive in your smartphones. You can find the specs of iPhone XS Max here: Apple iPhone XS Max