How to test/put to work TaskManager in iOS with Expo/React Native?

I'm developing an app with Expo which uses the TaskManager to run the application in the background. When I use the Expo client app to test my app, the code runs well, but iOS gives me a problem. I went to this link (https://docs.expo.io/versions/latest/sdk/task-manager/), on their documentation, where they say to include the following code in app.json:

{"expo": {    ..."ios": {      ..."infoPlist": {        ..."UIBackgroundModes": ["location","fetch"        ]      }    }  }}

I added this code to the app.json, but it still doesn't work. How to solve this problem?