Currently, 1Blocker is available in nine languages, and you can easily switch between them in your device settings.
On iOS, go to iOS Settings > Apps > 1Blocker > Preferred Language.
On macOS, the preferred language can be changed in System Settings > General > Language and Region > Applications > 1Blocker.
After that, you will need to restart 1Blocker to make it update the language and change the interface.