After opening Apex legends for the first time in the game I had this same issue showing update failed so I’ve done some of the things after which I was able to play the game without any interruption and as well as without any lag so let me tell you what are those things you should do to get rid of this update failed page on your android/ios mobile.
- Restart the game and if the error is still there then go to the second step.
- Firstly check your internet connection and speed of it, if it is good then turn off the wifi/cellular data for a second and turn it on then open the game(this trick worked for me).
- see if your game is downloaded fully or not if not then uninstall the game and reinstall it from the store.
- if you are not able to see the install option on the store then maybe your device is not applicable for the game.