How to use an older version of an application? I was using an application. Then the multiplayer mode stopped working, so I decided to reinstall it. After I uninstalled the app, I realised that an update had been made and my Android version is too old to use the new version of the application.

Is there anything I can do to be able to use the application again (except for buying a phone with a newer version of android)?

I checked, there are no updates of the system for my phone.

I downloaded the appplication via Google Play Store.
Clearly, the app's developer has changed the minimum API level for that particular app. So the latest version won't work on your version of Android.

You can side-load the APK file of an earlier version onto your device to get it working again.

You may request the app's developer for an older APK or you can download from other sites that provide APKs. APKMirror is a trusted repository, for example.