Welcome to the community, @melakukobo! You should be able to make configurations to your app as outlined in this support article (shared previously):
However, the first thing you should be cautious about is knowing the server on which you have created your account, as there are two public servers for KoboToolbox users. If you create an account under the Global Server and then try to configure your app with the EU Server settings, the configuration does not work. Similarly, if you create an account under the EU Server and then try to configure your app with the Global Server settings, the configuration does not work.
