The app is available in English (UK), English (US), German, French and Dutch since the version 3.5.0. It will automatically adapt to the language of your device. If however you want to choose another language than the one set on your phone, it's also possible. Here's how.
Head to your iPhone's Settings.
Find the Cowboy app in your app's list, and tap on it.
In the "Preferred language" section, select the language of your choice.
Make sure you're running Android 13 or later. Former versions don't allow you to select a language for an app specifically.
Open your Settings app your Android's phone.
Tap System Languages & input. App languages.
Select the Cowboy app and choose your preferred language.