缺少 use Str

app/Http/Controllers/DhammaTermController.php

@@ -6,6 +6,7 @@ use App\Models\DhammaTerm;
 use Illuminate\Http\Request;
 use Illuminate\Support\Facades\Cache;
 use Illuminate\Support\Facades\DB;
+use Illuminate\Support\Str;
 
 class DhammaTermController extends Controller
 {