Missing Purpose String in Info.plist File

With the engine version 4.21.2 + Xcode 10.2 I get this message that prevent the package to be uploaded on the AppStore

Missing Purpose String in Info.plist File. Your app’s code references one or more APIs that access sensitive user data. The app’s Info.plist file should contain a NSLocationAlwaysUsageDescription key with a user-facing purpose string explaining clearly and completely why your app needs the data. Starting spring 2019, all apps submitted to the App Store that access user data will be required to include a purpose string.If you’re using external libraries or SDKs, they may reference APIs that require a purpose string. While your app might not use these APIs, a purpose string is still required. You can contact the developer of the library or SDK and request they release a version of their code that doesn’t contain the APIs.

Into the folder:
Macintosh HD⁩ ▸ ⁨Users⁩ ▸ ⁨myName ▸ ⁨Documents⁩ ▸ ⁨Unreal Projects⁩ ▸ ⁨myProject ▸ ⁨Saved⁩ ▸ ⁨StagedBuilds⁩ ▸ ⁨IOS⁩
I’ve edited the file Info.plist with the following:

<string>Used to personalize Ads</string>
<string>Used to personalize Ads</string>

But those manually added lines disappear each time the game is cooked.

I found the location into the preferences of the project. Hopefully it should work.