Here you go: https://help.apple.com/xcode/mac/current/#/dev7ccaf4d3c

Ad Hoc provisioning profiles are usually only used for testing, since all of the target devices have to be registered in your developer account before signing the app. Also, Ad Hoc profiles expire after 12 months and the app needs to be re-signed and installed again.

You can install the signed app by using Xcode or Apple Configurator or "over the air" (see https://dev.to/gualtierofr/ad-hoc-distribution-for-ios-1524 for an example).