The dates and country (or countries) and language (or languages) for which the experiment should run will be stored in json format on mediawiki.
The app should query the config and turn the experiment on or off accordingly.
The current country of the app can be obtained by reading the Geojson string in the 'set-cookie' header of the API call to get the experiment config. See this [[ https://github.com/wikimedia/wikipedia-kaios/commit/ac601548a5866c648e630de536c7656659380c85 | commit ]]
The country code should also be added to the URL used to get the experiment data from the API.
The config will store in user local storage and expire the next day; in other words, the app will request the new config when it detects expiration.
Config page: https://www.mediawiki.org/wiki/Wikipedia_for_KaiOS/engagement1