No keyboard is presented when you try to enter text. Instead, you are prompted to speak into the microphone to type.
Teracube phones ship with a Gboard as the default keyboard app. Gboard is responsible for providing the system-wide keyboard for text input. If Gboard is disabled or uninstalled, the keyboard will no longer appear.
To re-enable Gboard, go to Settings > Apps & notifications > Tap “See all apps” > Then choose Gboard from the list of apps. Tap “Enable” to re-enable Gboard. The keyboard should work the next time you need to enter text.
If Gboard is missing from the list of apps, it may have been uninstalled. Open the Play Store, search for Gboard, then install it. Make sure the listed provider is “Google LLC”.