Its work perfectly. Dont need to write code for it.
First select project and then go in first tab “General”.
Now select “Devices” option in Deployment info section is iPad and in that down select Device orientation .. In which remove checkmark from landscape Left, Right option
After done select it back device as universal and set device orientation as portrait..mode and remove check mark from landscape mode.
Now run your app in iPad and check that things. I hope it will be resolved.