Android Studio - Cannot resolve symbol 'BuildConfig'

Question

I am trying to import

import com.example.app.BuildConfig;

but When I am doing so, this error is coming

Cannot resolve symbol 'BuildConfig'

and then I am doing this:-

TextView version = findViewById(R.id.version);
        version.setText(BuildConfig.VERSION_NAME);

and I am rececving this error:

Cannot resolve symbol 'BuildConfig'

there is a suggestion for the second error that I should import the class. But what should I import? these are the suggestions