I am trying to build my ionic 3 application and deploy and live reload on my device for that reason I am trying following command:
ionic cordova run ios --de
I had the same issue before and I fixed it by actually archive and validate the ios app using xcode GUI. That creates the provisioning profile you need if you check the "automatic managing signing". (P.s. If that fails to validate, then it is because of some other reason which you need to google) After all the necessary provisioning profiles are automatically created by xcode. Then, try run the command again. It should work this time! I hope that can solve your problem.