feat: add llm Select to KeywordExtractForm #918 (#1492)

### What problem does this PR solve?

feat: add llm Select to KeywordExtractForm #918

### Type of change


- [x] New Feature (non-breaking change which adds functionality)

web/src/pages/flow/duckduckgo-form/index.tsx

@@ -15,7 +15,7 @@ const DuckDuckGoForm = ({ onValuesChange, form }: IOperatorForm) => {
       form={form}
       onValuesChange={onValuesChange}
     >
-      <TopNItem></TopNItem>
+      <TopNItem initialValue={10}></TopNItem>
       <Form.Item
         label={t('channel')}
         name={'channel'}